Check out: https://bugzilla.redhat.com/show_bug.cgi?id=538156
I have too experienced several gnome-panel failures - either on boot or right-clicking on the workspace icons on the lower righthand side.
Do you have the Automatic Bug Reporting tool enabled? (you would need a redhat bugzilla account enabled) and the debuginfo installed (to allow backtraces).
---------- Post added at 11:18 AM CST ---------- Previous post was at 10:54 AM CST ----------
Sorry - a bit more practical advice. Remove the gnome-panel settings by doing the following:
At Boot - hit any key to get to the Grub window. Select your kernel you will log into (usually the latest at the top of the list. DO NOT press enter just yet - instead press 'a' key and edit the command line to include to something like this - in effect PUT the NUMBER 3
on the end:
kernel /vmlinuz-2.6.9-1.667 ro root=LABEL=/ acpi=on rhgb quiet 3
This will boot you into text-only.
Log in and run:
rm /home/ **your username**/.gnome/panel
This will remove your current gnome panel settings. Exit the text-mode by using the reboot command:
Allow F12 to boot as normal - do not enter and edit in the grub screen. Log in as normal.
If this has not worked I have found deleting additional gnome settings may help (but bear in mind you will lose any personalised settings). If you want to do this do the all of the above to get you in the text-mode and instead of removing just the panel settings remove ALL gnome settings by using the following command:
cd /home/**your username**/
rm -Rf .gtkrc .esd_auth .gconf .gconfd .gnome .gnome2 .gnome-private .gnome2-private .nautilus .thumbnails .metacity .themes .screensaver