Vista Key limits? Says my codes are invalid now

[ballmode]

So I bought a copy of Vista Ultimate from my university when I still was in school there. After reformatting my computer 2 times in the past 3 years, I just went to try to use it again. It works, but says I have 30 days to get a legit key. XP keys worked multiple times, am I doing something wrong with Vista?

 

[lxskllr]

My guess is it's a bug. You may need to call CS to get it straightened out.