Gigabyte Mobo/CPU/MEM question.

Hello all. First post, and I hope to be here for a while, its hard to find a good community to stick to these days!

Okay. So I have been getting some weird memory errors lately, usually if the computer freezes up I'll close a program and get one.

So I look on gigabytes website, and this is what I find...

"Because of chipset limitations, when using FSB 1333 MHz CPU with populating all DIMM sockets, memory frequency will be reduced from the original, and system instability or incorrect detection of memory module may be occur.
Please refer "Memory Support List" for memory support information."

SO. Let me see if I'm understanding this correctly. As long as I have the same processor I do now in it, I cannot populate both mem slots without this error?

If I cannot replace the processor, then if I stuck a single 4gb stick in would I stop receiving the errors?

Or if I put (dunno if this is even possible) a lower speed memory in (say 800mhz instead of 1066mhz) could I populate both?

I think in the end I'll probably just pull them both out and put in a 4gb stick so I can use the others for another system, but I just wanted to be sure I'm analyzing this correctly.

Thanks!

:edit:
Forgot, my system only registers roughly 3gb as being used, and says my video card is using 1gb from itself and 1gb shared for a total of a little over 2gb. Huh?