I've gone through a few:
512 MB - Danelectric(?) from Target - no problems over 9 mos, but I rarely use it now
2 GB Patriot from Fry's - have 2 of these, one for 7 mos., one I just got today.
2 GB PQI from Fry's - have one of these, returned it for hanging when playing video or music, got a replacement that seemed to wok for a while then crapped out I would avoid these if possible
4 GB SDHC by Transcend from Newegg - lots of problems using this one
- waiting to see if WM6 makes it work