A7N8X memory dimms configuration

Hi All =]
Just yesterday I was buying another mem dimm but a thought stopped me from doing this...
What I thought was: should my m.b. be able to handle two 256 mb and one 512 mb? (all dimms are DDR 400 rated)
Asus A7N8X has 6 banks (3 mem slots)...should I put the 512 mb dimm in upload channel mode and the other two 256 mb dimms in download channel mode? Should it work?
Thanks.

yes it handle max 3gig
u can put two 256 in first channel and the 512mb in the second and u will run in full dual channel mode

I heard somewhere that it wouldnt work, any proof of anyone actually doing it?

I have a 512 in the slot closest to the cpu, and 256's in the other 2, and it says it running dual channel in the post.

Thank you so much guys!