I have two A-Data 8 GB SDHC cards. One just died on me. I got them from newegg.com for prety cheap. Like $118 delivered. It does happen that i use the n800 quite a bit, and could be that i wore it out. More likely that the cheap card wasn't manufactured to the highest standard.

In the mmc1 slot, the card would simply stop allowing writes, even though the filesystem was mounted as read/write. I swapped cards in the slots, and now the bad one wont even mount.

I will likely go with a better brand, and may look for a higher class card for better performance.