Tim....
first off try to FORMAT the
Thumb drive IN YOUR S900 see if that works.....if not there are other options this happened on my T2 and I had to keep trying different brands until I found one that was compatible with the unit....

Corsair Voyager TD seems to work the best for me ..
http://www.corsairmemory.com/products/voyager.aspx



[This message has been edited by Dnj (edited 10-10-2007).]