Ran into an interesting tidbit recently - if you dual boot your machine with XP and Win 7 for example, there is apparently an issue where XP does not recognize the format of the Win7 restore points if it can see the win7 partition so it will delete your win7 restore points for you. I am running a dual boot config (XP and 7) and a quick test didn't seem to remove my win7 restore points, but it may be that XP has to be looking at the disk or something - it is not clear exactly when XP deletes the win 7 restore points, but it is fairly well documented that it does happen. Something to be aware of - here is a link to a Microsoft KB article on the issue - a Google search for "xp deleted windows 7 restore points" turned up lots of info on the problem (and some work arounds that include hiding the Win 7 partition from XP with a registry hack).
http://support.microsoft.com/kb/926185
http://forums.cnet.com/7723-19411_102-399058/why-are-my-windows-system-restore-points-disappearing/

By the way - HAPPY HOLIDAYS !!
mikey