diff --git a/twidere/src/main/java/org/mariotaku/twidere/activity/MediaViewerActivity.java b/twidere/src/main/java/org/mariotaku/twidere/activity/MediaViewerActivity.java
index effdeef68..c1129531b 100644
--- a/twidere/src/main/java/org/mariotaku/twidere/activity/MediaViewerActivity.java
+++ b/twidere/src/main/java/org/mariotaku/twidere/activity/MediaViewerActivity.java
@@ -685,7 +685,7 @@ public final class MediaViewerActivity extends BaseActivity implements Constants
             super.onDownloadStart(total, nonce);
             if (mMediaDownloadEvent != null && mMediaDownloadEvent.getNonce() == nonce) {
                 mMediaDownloadEvent.setOpenedTime(System.currentTimeMillis());
-                mMediaDownloadEvent.setSize(nonce);
+                mMediaDownloadEvent.setSize(total);
             }
         }
 
@@ -755,8 +755,8 @@ public final class MediaViewerActivity extends BaseActivity implements Constants
                     decodeBitmap(cr, uri, o);
                     final DisplayMetrics dm = context.getResources().getDisplayMetrics();
                     final int targetSize = Math.min(1024, Math.max(dm.widthPixels, dm.heightPixels));
-                    o.inSampleSize = TwidereMathUtils.nextPowerOf2((int) Math.max(1,
-                            Math.ceil(Math.min(o.outHeight, o.outWidth) / (float) targetSize)));
+                    o.inSampleSize = TwidereMathUtils.nextPowerOf2(Math.max(1,
+                            Math.round(Math.min(o.outHeight, o.outWidth) / (float) targetSize)));
                     o.inJustDecodeBounds = false;
                     final Bitmap bitmap = decodeBitmap(cr, uri, o);
                     if (bitmap == null) throw new IOException();
@@ -854,7 +854,7 @@ public final class MediaViewerActivity extends BaseActivity implements Constants
             super.onDownloadStart(total, nonce);
             if (mMediaDownloadEvent != null && mMediaDownloadEvent.getNonce() == nonce) {
                 mMediaDownloadEvent.setOpenedTime(System.currentTimeMillis());
-                mMediaDownloadEvent.setSize(nonce);
+                mMediaDownloadEvent.setSize(total);
             }
         }
 
@@ -1153,7 +1153,7 @@ public final class MediaViewerActivity extends BaseActivity implements Constants
             super.onDownloadStart(total, nonce);
             if (mMediaDownloadEvent != null && mMediaDownloadEvent.getNonce() == nonce) {
                 mMediaDownloadEvent.setOpenedTime(System.currentTimeMillis());
-                mMediaDownloadEvent.setSize(nonce);
+                mMediaDownloadEvent.setSize(total);
             }
         }
 
diff --git a/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorActivitiesFragment.java b/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorActivitiesFragment.java
index 235d91d50..cddc7dc9a 100644
--- a/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorActivitiesFragment.java
+++ b/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorActivitiesFragment.java
@@ -208,7 +208,9 @@ public abstract class CursorActivitiesFragment extends AbsActivitiesFragment {
             @Nullable
             @Override
             public long[] getMaxSortIds() {
-                return DataStoreUtils.getOldestActivityMaxSortPositions(getContext(),
+                final Context context = getContext();
+                if (context == null) return null;
+                return DataStoreUtils.getOldestActivityMaxSortPositions(context,
                         getContentUri(), getAccountKeys());
             }
 
@@ -243,7 +245,9 @@ public abstract class CursorActivitiesFragment extends AbsActivitiesFragment {
             @Nullable
             @Override
             public long[] getSinceSortIds() {
-                return DataStoreUtils.getNewestActivityMaxSortPositions(getContext(),
+                final Context context = getContext();
+                if (context == null) return null;
+                return DataStoreUtils.getNewestActivityMaxSortPositions(context,
                         getContentUri(), getAccountKeys());
             }
 
@@ -266,7 +270,9 @@ public abstract class CursorActivitiesFragment extends AbsActivitiesFragment {
     }
 
     protected String[] getNewestActivityIds(UserKey[] accountKeys) {
-        return DataStoreUtils.getNewestActivityMaxPositions(getActivity(), getContentUri(), accountKeys);
+        final Context context = getContext();
+        if (context == null) return null;
+        return DataStoreUtils.getNewestActivityMaxPositions(context, getContentUri(), accountKeys);
     }
 
     protected abstract int getNotificationType();
@@ -282,7 +288,9 @@ public abstract class CursorActivitiesFragment extends AbsActivitiesFragment {
     }
 
     protected String[] getOldestActivityIds(UserKey[] accountKeys) {
-        return DataStoreUtils.getOldestActivityMaxPositions(getActivity(), getContentUri(), accountKeys);
+        final Context context = getContext();
+        if (context == null) return null;
+        return DataStoreUtils.getOldestActivityMaxPositions(context, getContentUri(), accountKeys);
     }
 
     protected abstract boolean isFilterEnabled();
diff --git a/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorStatusesFragment.java b/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorStatusesFragment.java
index e5cade1fd..62056198a 100644
--- a/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorStatusesFragment.java
+++ b/twidere/src/main/java/org/mariotaku/twidere/fragment/CursorStatusesFragment.java
@@ -267,7 +267,9 @@ public abstract class CursorStatusesFragment extends AbsStatusesFragment {
             @Nullable
             @Override
             public long[] getMaxSortIds() {
-                return DataStoreUtils.getOldestStatusSortIds(getContext(), getContentUri(),
+                final Context context = getContext();
+                if (context == null) return null;
+                return DataStoreUtils.getOldestStatusSortIds(context, getContentUri(),
                         getAccountKeys());
             }
 
@@ -307,7 +309,9 @@ public abstract class CursorStatusesFragment extends AbsStatusesFragment {
             @Nullable
             @Override
             public long[] getSinceSortIds() {
-                return DataStoreUtils.getNewestStatusSortIds(getContext(), getContentUri(),
+                final Context context = getContext();
+                if (context == null) return null;
+                return DataStoreUtils.getNewestStatusSortIds(context, getContentUri(),
                         getAccountKeys());
             }
 
diff --git a/twidere/src/main/java/org/mariotaku/twidere/fragment/card/CardPollFragment.java b/twidere/src/main/java/org/mariotaku/twidere/fragment/card/CardPollFragment.java
index 874abb382..e8a057143 100644
--- a/twidere/src/main/java/org/mariotaku/twidere/fragment/card/CardPollFragment.java
+++ b/twidere/src/main/java/org/mariotaku/twidere/fragment/card/CardPollFragment.java
@@ -131,7 +131,8 @@ public class CardPollFragment extends BaseSupportFragment implements
     }
 
     private void displayPoll(final ParcelableCardEntity card, final ParcelableStatus status) {
-        if (card == null || status == null) return;
+        final Context context = getContext();
+        if (card == null || status == null || context == null) return;
         mCard = card;
         final int choicesCount = getChoicesCount(card);
         int votesSum = 0;
@@ -199,7 +200,7 @@ public class CardPollFragment extends BaseSupportFragment implements
             }
         };
 
-        final int color = ContextCompat.getColor(getContext(), R.color.material_light_blue_a200);
+        final int color = ContextCompat.getColor(context, R.color.material_light_blue_a200);
         final float radius = getResources().getDimension(R.dimen.element_spacing_small);
         for (int i = 0; i < choicesCount; i++) {
             final View pollItem = mPollContainer.getChildAt(i);
@@ -237,12 +238,13 @@ public class CardPollFragment extends BaseSupportFragment implements
 
         final String nVotes = getResources().getQuantityString(R.plurals.N_votes, votesSum, votesSum);
 
-        final CharSequence timeLeft = DateUtils.getRelativeTimeSpanString(getContext(),
+        final CharSequence timeLeft = DateUtils.getRelativeTimeSpanString(context,
                 endDatetimeUtc.getTime(), true);
         mPollSummary.setText(getString(R.string.poll_summary_format, nVotes, timeLeft));
     }
 
     private void displayAndReloadPoll(ParcelableCardEntity result, ParcelableStatus status) {
+        if (getHost() == null) return;
         displayPoll(result, status);
         getLoaderManager().restartLoader(0, null, this);
     }