I would like to state that I have a N810 and a SanDisk 6GB microSDHC card in a SanDisk MicroSD(HC) to MiniSD(HC) adapter and it works perfectly, and displays, out of the box, under 'file manager' 5.69GB of space available.

I haven't tried the card in any other device, as I said, it's out of the box, let me know if you want any other details, but I think it's all said.