i recently bought the motherboard mentioned above with a core duo 64 processor and i was wondering if i could use a 533 ram chip with it. the box says it supports ddr2 800, but i was wondering if it could support a 533 chip since its much cheaper.
thanks for any help

You will want to use DDR2 800 in dual channel

but is a 533 still compatible?

yes

does it NEED to be dual channel?

No, but you will get better results if you have a matched pair of RAM to take advantage of dual channel.
Here's is an example of price differences that I've found on newegg.com:

DDR2 533mHz 2x1gig chips (dual channel set) cheapest that they have
$71 shipped
pqi POWER Series 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 533 (PC2 4200) Dual Channel Kit System Memory - Retail
http://www.newegg.com/Product/Prod [...] 6820141224

DDR2 800mHz 2x1gig chips (dual channel set) cheapest that they have
$80 shipped - $15 MIR = $65 shipped!!
A-DATA 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
http://www.newegg.com/Product/Prod [...] 6820211066

You decide which one is cheaper. I'd go with the DDR 800mHz A-Data ones, for the simple fact that they are faster and cheaper, but that is just me.

My 2cp's

wow nice deals!!
thanks for the info
and i would also go with the 800 for obvious reasons