For me, buying the 4GB card off of ebay (from pc2buy) is how I came to register for this site. When I received the card a week or so ago, my 6700 would not read it so naturally I felt that I got ripped off. I was all set to send it back when, as a last ditch effort, I did a google search and found this thread with the advice to try reformatting the card. I just got a chance to do this last night and it works as advertised. I stuck the card in the SD slot on my desktop and got a command prompt and issued "format d: /fs:fat32". I then stuck the card in my 6700 and it was instantly recognized. I'm still in the process of syncing over all of my Urge music as well as many MB's of marine charts but so far it works great.