From the ASUS specifications for that motherboard:
- 4 x 184-pin DIMM Sockets support max. 4GB DDR400/DDR333/DDR266 non-ECC
un-buffered DDR SDRAM memory
- Dual Channel Memory Architecture
Personally, I only buy ECC memory and motherboards that support it (currently running on an ASUS K8V SE Deluxe). There's also ChipKill (PDF)
support in this motherboard, which is essential with larger memory sizes.