Force Close when backing out of a user/tag/group before load completed

[rpcutts]

Possible dupe of #662529

If I navigate to a user/tag/group timeline and while the dialog reads "Fetching Notices... Please wait..." I press the hardware back button once the dialog hides, if I press it again before any notices appear it leaves the page as expected but then Force Closes.

"The application Mustard (process org.mustard.android) has stopped unexpectedly. Please try again"

I can achieve the same result when launching the app. If the timeline is blank and the fetching notices dialog appears, pressing back twice before any notices appear exits the app but then shows a Force Closed dialog.

Mustard 0.1.9.7a
Android 2.2
HTC Desire