Nope, I didn't find a solution for the seatbelt issue other than to unplug both the driver and passenger sensors. It's easily done, the connectors are ender each seat.
It seems that there may be some issue with the converter that is available on ebay (that's ehere I got mine).
The converter from cartek works no problems at all. If you're not happy about unplugging the seatbelt sensor, then the only other option I can see is to give cartek a mail and purchase a new converter.
Russ