I bought a 16GB Transcend SD card for my N800, which died shortly after. I sent it back, and its replacement died just as quickly. In both cases it seemed to be hardware fault, not just a corrupt filesystem or partition table.

In comparison, my SanDisk cards have been rock solid, even under heavy use. One's been through the washing machine and dryer, and still works perfectly.

So, my solution to the problem is to stop buying cheap cards.