Like ChrisFix stated, the Transend "SDHC" 4GB miniSD cards will not work with the 6700 at this time.

That said, I have been testing a couple generic 4GB non-SDHC cards (formatted to FAT32) with limited success for the last month or so... To clarify, the cards work for the most part, but they have corrupted SKtools (installed to the card), and have caused some lockup issues on power up. Anyway, if I remove the 4GB, and stick a 2GB card in with the exact same programs etc... (just less audio video files), the problems go away completely.

On that note, if you're not going to run many programs off card, the 4GB non-SDHC cards appear to work alright with Pocket Player and audio files, as well as iGuidance and it's maps installed to the cards. Nonetheless, I still do not trust these larger cards with the current 6700 card driver and FAT file structure. Further, I've found that these 4GB cards have problems correctly transferring specific programs like Pocket Player, when backing up to a PC with USB2.0 card readers. And again, there are no problems with the 2GB cards formatted to FAT.

Please note that your mileage may vary...

BTW, there's already a thread here in regard to 4GB cards. So I'm guessing this thread will be merged with it soon. Just in case you're looking for it later..

Hope this helps,
R