Dual-Boot Vista and XP = No System Restore!
The only drawback I've found is that XP automatically deletes the System Restore files in Windows Vista. There does not appear to be a feasable work-around ... and yes I've even tried hiding the (Vista) drive using Tweak UI in Windows XP (doesn't work) ...
So a word to the wise ... prior to any major install of either software or hardware (even drivers) make sure you create a Restore Point and do not boot into XP until you are satisified that everything is working properly.