Kinda sounds like your system is checking what monitors are connected.
When it tries a different port, your monitor gets disconnected, goes to sleep, the system switches back to it and it wakes up...
dunno...
Check whether there's a setting in BIOS that controls this, or check whether you've connected the monitor to the correct output port on the vid card.
Hm, waitaminute, windows 7 aint it?, Hm... not sure, could be normal with that one. I can test if it does anything similar on my system... hold on... I'll be back...
EDIT: I'm using dual boot, so that's no good, can't really compare, sorry...