Kodak recently posted a firmware upgrade 1.02 for the DX3900. It's suppose to clear up issues with USB support. Thought you would like to know. For firware update goto:
http://www.kodak.com/global/en/service/software/dx3900/dx3900Software.jhtml ;jsessionid=2CWZKQZD5B5DZQHIO2SXWKA#FirmWin
http://www.kodak.com/global/en/service/software/dx3900/dx3900Software.jhtml ;jsessionid=2CWZKQZD5B5DZQHIO2SXWKA#FirmWin