The changes between 1.60 and 1.62 are slight changes in the status LED. There is no compressor related change between the two.
If your having trouble with your PCM, go to the self-test page of the roboRIO web-page configuration.
Jump to "Self Test"...
http://wpilib.screenstepslive.com/s/...ribution-panel
This will tell you...
(1) -if the PCM is enabled (robot is enabled)
(2)- if the pressure-switch is closed (pressure is not full)
(3)- if the compressor-output is on
(3) requires (1) and (2) regardless of which firmware is used.
Does the compressor turn off when the robot is disabled? If not then it sounds like the compressor ground input is shorting to robot ground somewhere outside of the PCM.
When the compressor is on, is (1),(2),(3) reported in the self-test?
Another easy check is to just disconnect the pressure switch. The PCM has two weidmuller connectors that normally go to the pressure-switch. When the pressure-switch signals not-full, it shorts the two leads together (relay). When the pressure-switch signals full, the two leads are open. So if you short the two BLUE PRESSURE SW. connectors on the PCM with a wire, instead of connecting to pressure-switch, PCM will behave as though the pressure-switch reads not-full. Remove the wire and PCM will behave as though pressure-switch reads full.