Again,..not trying to pee in your Wheaties,..but if your "pressure test" was pressing the plunger on the schrader and it said PSSST, that is not an indication of still having pressure. For the system to be so low for the cutoff switch to interrupt the compressor, the system probably only has residual air pressure left in it.
AC systems don't routinely lose freon unless there's a reason. Somewhere in your system there is a leak.
Well it didn't really come out and say it. It was more of a whisper. Hopefully this weekend I can pull a vacuum on it and see if it holds. I got an email this morning saying my hubs - which were supposed to be here in 2 days - will be here next week. Ghey.