I'm going to venture a guess and say no it's not common. Unless of course it's a settings problem. See if you can up the refresh rate at all. Whenever i use pcs with anything less than a 60hz refresh rate i get a headache. But that's usually for CRT monitors. Worth a try.
I've noticed this once or twice on my 24" iMac, it only seems to happen in Windows XP though (not at all in OsX) so I think it could be a Windows thing.
If it's happening constantly I'd get it checked out if I were you.