With today's rawhide, when I enable desktop effects and then use the screen resolution tool (gnome-display-properties) to change the resolution, it appears that the desktop hangs. The resolution changes, but the "do you want to keep this" box pops up with no text and no buttons. The panel also loses its buttons. The mouse works (but I can't do anything - no dragging windows around or anything), but the timeout hits (because I didn't ack the new res), and the display switches back to the old resolution. However, the desktop is still dead. I can kill X with CTRL-ALT-BS. If I turn off desktop effects, I can change the resolution. Then I can re-enable desktop effects. I am not sure if this points to compiz or what (but it seemed like the place to start). This is on an Athlon64 with an ATI Radeon 9200 Pro (RV280).
Since this bugzilla report was filed, there have been several major updates, which may have resolved this issue. Users who have experienced this problem are encouraged to upgrade their system to the latest version of their distribution available. Please, if you experience this problem on the up-to-date system, let us now in the comment for this bug, or whether the upgraded system works for you. If you won't be able to reply in one month, I will have to close this bug as INSUFFICIENT_DATA. Thank you.
This might be something about the driver -- please, attach your X server config file (/etc/X11/xorg.conf) and X server log file (/var/log/Xorg.*.log) to the bug report as individual uncompressed file attachments using the bugzilla file attachment link below. Could you please also try to run without any /etc/X11/xorg.conf whatsoever and let X11 autodetect your display and video card? Attach to this bug /var/log/Xorg.0.log from this attempt as well, please. We will review this issue again once you've had a chance to attach this information. Thanks in advance.
Chris, any interest in this bug yet?
Sorry for the (extremely) delayed response; I haven't been able to test on this particular system much. With late F8 development trees, I had all kinds of random problems with compiz on this system, but now that I've installed F8, it seems to just work, and I don't have a problem changing resolution after enabling compiz.