motherboard help

[WeeGeez]

Here goes.. I've just upgraded to 4GB ram up from 2 so now I've got four 1GB DDR2 - 4200 sticks. I'm not buying any more lol..

Dilema is I'm still on 32bitXP and upon installing this extra 2GB my system became very unstable with 4gb, often crashing including increase in CTDs. researched online, and discovered that a simple bios update from acer website would resolve this issue. So I did (stupidly without creating backup) and my system indeed became solid and never crashed again, which I was glad about...
Untill
Another problem this time with my soundcard X-FI - more so increased PCI latencies when graphics and sound were coinciding - introducing crackling/static issue. (Used latency checker to discover this was the cause). Apprently this is very common with the nforce 4series mobo's, the very one I have... fml.

So.. I want a new mobo, as the one I have has been a pain in the _ since day one.
will this do the trick? i noticed it supports 1200 DDR2 RAM but mentions nothing about 4200 that I currently have. really unsure about this

Should I even bother getting a mobo with 4 ddr2 slots at all? The ram I currently have is the only option I dont want to fork out for more..
I'm pretty sure any new mobo will be stable with 4gb in 32XP though

Any other suggestions would be great, keeping in mind it must allow for:
AMD Athon 64 x2 CPU
4GB of DDR2 4200 Ram (if 4200 makes a difference)
and consist of one PCIe x16 slot.

EDIt link above just noticed mobo is rectangular and wont likely fit into my current machine ..