Monitor fails to wake up

I've had this problem for a while I just fixed it by turning off hybernation mode so my monitor doesn't go to sleep when I'm idle.

Problem: When I leave my computer idle the monitor goes to sleep but will not wake up when I jiggle the mouse around or any thing, yet my CPU does wake up and appears to be running fine.

Problem noticed: When I upgraded my graphics card from a integrated ATI X200 series to a GeForce 6600 OC 512mb.

System information: Computer is a 2005 HP Pavilion a1250n with XP media center service pack 2, monitor is a HP f1905 19''.

Although this problem isn't a nessesary fix it would be nice to fix it, so I can put it in hybernation when I go to bed because it's not the quietest system.