I have a 1gb and a 2gb stick in dual-channel. What are you guys talking about?
Dual-channel used to be reliant on matched pairs of RAM, and as far as I know motherboards for the Pentium E6300 still do.
I know that multi-channel RAM operation isn't as strict as it used to be when it first came out (i.e. matching RAM speed and latencies are enough), but I wasn't aware that Intel chipsets allowed dual-channel operation with unmatched DIMMs.
Regardless, it's all a bit off-topic between malmental and I anyway - the point is 3GB RAM is perfectly fine for Windows 7.