Although you should be using software version 2.0 final (or at least 2.0 beta 13, which is probably better if you use the tuner a lot), that's of course got nothing to do with your tuner issues.

It's good that you confirmed the wiring loom was OK, which would have been our first suggestion.

If there's a way to do it, double check that the antenna wire and the car's antenna is working as intended. You said that plugging and unplugging the antenna wire didn't make any difference, so that makes either the antenna wire or the tuner itself suspect. If you don't have another car stereo lying around to temporarily plug in, I don't know if the antenna wire is something you can easily test or not.

If you can rule out a problem with the antenna, then definitely crack open the tuner module and have a look inside. Maybe the jack that holds the antenna connector has a broken solder joint or something?

Beyond that, if you can't see anything visibly wrong with the tuner module, then it's probably time to send it to support or eutronix.