kernel-2.6.22.5-71.fc7 from updates-testing doesn't hibernate properly on a Dell Latitude D800. It starts hibernation but seems to hang at (IIRC) "shrinking memory" or something similar (can check if needed). It worked with previous, released F7 kernels.
Suspending fails with kernel-2.6.22.5-71.fc7 for me (on a Dell Latitude D600) as well. The console prints: Stopping tasks ... but then nothing else happens. 2.6.22.2-57.fc7 worked fine; I haven't tested the intervening kernels.
(Nils, could you update the summary to say "doesn't hibernate/suspend properly" instead of just "doesn't hibernate properly"? Thanks...)
Fixed in 2.6.22.5-76
Adjusting the summary so people find this when they're searching...