constrast problem

[razerindemix]

Hi
I was sitting at my moniter the other night and thought the windows i have open were relly bright and the words were almost blurred but my wallpaper looked normal
so i went and tweak the constast & brightness & gamma saved profile thinking it was down to whatever and next day playing quake 4 i thought funny this is looking relly dark
so i went to exit and then it suddenly the screen flashed back a much lighter constrast and did look normal again so i exit quake and then also my desktop flashed a couple of times from normal to dark and back normal but now as not changed for a while even when i play quake 4

but it is darker than it ought to be

what is going on !

what can i do part from checking my conections which i recently fitted a new dvi -dvi lead it's a llyama prolite e431s \ AMD 2800XP \ RADEON X8OOPRO 256MB \ XP

many thanx