I know you have reformatted the CF card, but I thought this information may help. You may have to many files in the rute directory. You may also be having problems with the fire wall on the system. I also found the following, that may help. I'm pasting it from the manual. Update Firmware Pressing the Update Firmware button makes Book Port Transfer check the firmware for updates. If firmware updates are available, Book Port Transfer lets you know and asks if you would like to download and install these updates. You must be connected to the Internet for this option to work, and Book Port must be connected to your computer, so the software can see the unit's version number. Updating the firmware on your device is serious business, so it is recommended that you perform this action only after taking some precautions. First, insure that your battery level reports at least 50% capacity. Next, never attempt a firmware update while using rechargeable batteries. If you use Windows ME or Windows 2000, use the scandisk or chkdsk utility to insure that your Book Port's flash card is free from errors. Under Windows XP, you should use the Error Checking option under the properties for the disc. Once you download a firmware update, Book Port automatically applies the update as soon as you disconnect the unit from the USB connection. It is a good idea to connect your ear buds and put them in your ears before you disconnect the unit from the USB port, so you may hear the messages that get announced as Book Port updates its firmware.