Dynex doesnt have an update. I also have the Dynex DX-UBDB9 cable, and found the following driver that
works like a charm in Windows7 (even at 64 bit).
The driver you need is this one:
PL2303_Prolific_DriverInstaller_10311.z ip
Download it at this site:
prolific.com.tw
Remember to unplug anything plugged into your USB ports, install the software, reboot the computer, plug in
the USB-Serial Cable (but disconnect it from what it is attached too, ie, a GPS unit), and windows7 should recognize it.
then plug in your GPS, or what ever into the cable and you should be good to go.