AC problem, 2000 TDI Jetta

I have a 2000 TDI Jetta that has an AC problem. The AC was working fine one day, and only blowing hot air the next. This occurred in 100+ degree heat in San Antonio. I've checked, and the fans and clutch seem to be working fine. With the AC off, the two fans at the radiator are off and the AC compressor is not running. When turning on the AC, both fans run, and the compressor is turning. I don't hear any unusual sounds. All of the fuses at the battery seem to be fine, and I don't find any fuses in the drivers side fusebox that look bad. After all the above, I wanted to check the refrigerant. The simple low pressure gauge I got seems to indicates that the refrigerant is fully charged (above 55 @ ~95-100 degrees). I don't have a way to check the high side pressure.

Does this suggest than the compressor is the problem, or is there anything else I should be checking? Unfortunately, I am not at home (at military training in San Antonio), so I don't have access to most of my tools. Is there anything anyone can suggest to further troubleshoot or fix the issue?

I did notice one strange thing, but I don't know if its significant. In the evening, when the temperature is cooler, if I turn on the fans (AC off but the dial set to cold) the air through the vents is noticeably hotter than the outside temperature. Previously, I'm pretty sure that I would get the ambient air temperature through the vents. Is this a sign of anything?

Thanks!
Sean

Same thing happened to me.
Here is the solution:
http://forums.tdiclub.com/showthread.php?t=337702&highlight=hot+air