Noticed problems in the Facebook app for iOS in the last couple of days? It's got to do with a recent update that you may (or may not) have downloaded and installed.
Early Tuesday afternoon, Facebook updated its app for iOS (now version 5.6). The update now allows you to change your cover image directly from your iPhone with a couple of finger taps. It also makes it easier to start a group message.
To update your cover image: Simply tap on your cover image in profile view and select either Choose From Library or Take Photo. Select your photo, arrange then save.
But only once you've installed the update. Find it here. Note, too, that this only works on the iPhone, and not on the iPad - for reasons unbeknownst to us.