Get nauseated, headachy after playing game, anyone else?

[prettywoman]

Get nauseated, headachy after playing game, anyone else?

I know this sound weird, but it happened 3 separate times after playing Penumbra on my PC today.
Is it just me? Coincidence? Something else going on?
Anyone else experienced this?
Caused by a "flicker" of the screen I can’t perceive?
Never ever had this happen before. Told you it is weird, any thoughts?
BTW: Just started playing the game today, have GREAT fun so far with the exception of this “situation”. :cry:
PW