The current version of lxpanel in rawhide (0.3.999) was reported to crash for at least one user (https://bugzilla.redhat.com/show_bug.cgi?id=496833). The final version of lxpanel, which was released some days ago, fixed this crash. So lxpanel-0.4.0-1.fc11 should be tagged as f11-final to avoid a crashing app in the final release.
lxpanel-0.4.0-1.fc11 was tested by me since it was build and it worked fine. Additionall tests were made by cwicket (the co-maintainer) and it was reported to fix the crash by the bug starter.