I just installed the Fedora 16 beta on my laptop. I used the GNOME iso file. Everything went fine during the installation. When I logged in after the installation I decided the first thing I would do is install a certain package and check for updates as well. Finding a package in add/remove software didn't work, it just kept searching forever. Then I opened software update and figured out the problem: when I hit 'check now' I got an error message reporting there was a problem connecting to a software source, giving the detailed error message: 'database disk image is malformed'.

This forum post [1] provided a workaround in the second post which did not work for me. May be related to bug #642913, but that bug was apparently triggered in Anaconda while mine occured when I was logged in to GNOME. Because the other bug also affected F14 I thought it was better to file a new bug.

[1] http://forums.fedoraforum.org/showthread.php?t=260195