Ram-LAN help if you can

Hello peeps, just got a new build and am trying to iron out the bugs so I'm trawling for info and help.
First off I'm running with only two sticks of ram (2x1gb at 800 mhz) as when I put the full 4 sticks in I get lots of BSOD's before system finally boots. I thought updating vista would sort this out but no.
Installing the 4 gigs of RAM had unexpected side effects. After I removed two of the sticks for system stability I found my wireless connection (which had been working fine until then) was acting strange. It would loose connection at random with the wireless network becoming 'invisible' then it would cycle between local, local and internet and no connection. Even when it was connected the speed was so slow I needed a shave after loading up a web page.
My wireless adapter it a buffalo wireless-G PCI adapter. I had problems installing the manufacturers drivers for this which was solved after a clean install with the adapter in place. Then vista assigned broadcom drivers and these worked fine before I put in the four sticks of ram.
My quiery is this, how do I get my connection back as good as it was and also why does installing four gigs of ram cause such a problem as I'm experiencing?

OS Vista ultimate 64
MB Asus Striker 2 formula
CPU Intel Core 2 quad Q6600
GPU x2 XFX 8800 GT in SLI
Mem 4GB (4x1GB) G.SKILL PC2-8500 DDR2-1066
(running with 2x1Gb at 800mhz at the moment)
HD Samsung Spinpoint T166 500GB
Mon Samsung SM2232BW - 22" Widescreen TFT Monitor
Case Antec performance one P180
PSU with Antec TPQ 850-EC
Bios Same as came with the board

Note: I have a basic knowledge of these things so be gentle with me.