I have a problem in one of my apps when I start it from a notification. It never appears in the \"recent app\" list.
Without notifications, every thing works as expected
I bumped into same issue. The problem was that my activity had android:label="". When I open Activity from the Notification then it replaces root activity in the app task with current one. And Android excludes activities with empty label from Recents (see source code).
To hide title of activity you should use:
getActionBar().setDisplayShowTitleEnabled(false);