Need help, choosing new memory

My systemis configured this way:
Asus A8N-SLI Deluxe
Amd Athlon 64x2 4400+ (1mbx2 L2cache)
2 Corsair CMX 1024-3200C2 (Twin)
Windows XP pro SP2

Need to upgrade my memor and want to still using my 2 stcks of corsair memory.
Do i have to buy the same memory or what or manufacturer…, recomendations…
I want 1 or 2 gigabite of more memory.
Thanks in adfvance

Well, I believe your limited to a maximum of 4GB RAM total. For best results in compatibility, it would be in your best intrests to purchase another two sticks of the 1024-3200C2 part. Alternatively, you could go with 2 2GB sticks and not have to worry about matching with your current set.