This thread as been floating around long enough, I should have added my $0.02 by now. Of course, the US dollar is down on most currency exchanges, so my $0.02 is probably only worth $0.01 in 2006 money.

OK, terrible joking aside, like Pete I have a Kingston 8GB Class 6 SDHC card in the internal slot. I've had it there for around a month now, and I have experienced no problems. I have not, however, tried to enable the swap file because of others' reported problems with it. I previously had used the included 128MB miniSD card as swap with no problems, but I've been doing without since the 8GB Kingston took up residence.

The external slot, however, was another story. Though I had used various 1GB and under SD cards in my external slot with no problems (and continue to do so), using the Kingston 8GB in the external slot caused some odd behavior. For the first week or so, it merely unmounted at odd times; I wouldn't even notice it had disappeared from the system until Canola updated its database and insisted there was no music for it to play. Opening the slot and removing and reinserting the card always brought it back to normal. This continued for about a week, and then an application (I forgot which) complained about a corrupted file. I tried looking at the card on my PC using a reader I thought was SDHC-certified (it wasn't). The PC wanted to format the card, which freaked me out as that's similar to what others have experienced when their card was toast. Since I wasn't sure about the reader though, I pulled the card out of the reader and put it in the only other device that I was sure supported SDHC, my Treo 680. It confirmed the card now needed formatting, but it formatted the card successfully, and I was able to copy some Treo files back and forth. I removed the card from my Treo and, based on some others' experiences, I decided to try the card in the N800's internal slot. I copied over my data from a backup, and everything has been fine since.

Although my card's corruption definitely started in the N800's external slot, I'm not sure if it or the bad card reader is to blame for wiping out the directory structure (or perhaps even interaction between the two). After the incident, the card has worked fine in the internal slot, and that's where it's staying.