What do you hate about Vista? How about trying to resolve the problem? It's a much better OS on so many levels, though I'm sure it feels a bit alien at first if you don't like change. It is, however, worth sticking with.
Also, downgrading will be a pain: you'll have to format your disk and you'll have to have a full copy of XP, which will cost you a bit. Is it really worth the hassle when a spot of perseverance might do the trick?