Need help with evga mobo and AMD 4200+ AM2

[A4bMercenary]

ok i have and evga 590sli socket AM2, 4200+ amd,2 gigs a-data 800, 8800gt, 200gig hd. The cpu and video card are watercooled. but i having a problem overclocling my cpu sence i put my new ram in. i had 2gigs of 533 and overclocked cpu to 2.9ghz. Now i cant even get to a 2.5. The ram goes up everytime i take the cpu up. any ideas on why my ram goes up? Thanks