Have you checked to make sure the cabling is correct? In other words, none of the pins have pulled out of the connectors anywhere (sled, extension, etc.)

Also have you looked at the FAQ entry on this topic?

Also did you by any chance apply a Mk1 upgrade file to your Mk2?

It kinda sounds like the antenna amplifier in your car suddenly quit working, or the antenna plug became broken or frayed internally.

Also there is a known bug in 2.0b3 where sometimes the tuner doesn't properly activate the power antenna wire. See if different combinations of booting, sleeping, etc will wake it up and make the power antenna wire come on.