New motherboard!!! MSI 790FX-GD70

Okay so right now I am running:

Motherboard: MSI-K9A2cf-f
CPU: Amd Phenom X4 9500
Ram: 4gigs OCZ Black Widow 1066 DDR2
Video Card: ATI 4870X2
Vista 32bit

I get "appcrash" alot in certain mmo's in really crowded areas, of course this is very annoying. What makes it really annoying is I can play any brand new game out there just fine, but I play mmo's so with me playing AION alot, it is really frustrating when it crashes. Basically though I am buying a new motherboard and processor in my first update the MSI 790FX-GD70 AM3 AMD 790FX ATX AMD and AMD Phenom II X4 965 Black Edition Deneb 3.4GHz. Will it be okay until my wallet becomes a little fatter to run the DDR2 ram off of this? I am hoping this will fix my problem because I know the first Phenoms were not any good. After awhile I will up date ram and then video cards. But I feel the problem is the processor. Any thoughts on if this has a shoot on fixing it as well as if running DDR2 ram for a few months will work just fine would greatly help.