Have you tried all of the Zorro slots? Perhaps you are not getting enough power to your Zorros. I am sure there's a way to test the power output with a voltmeter. Do other Zorro cards work in your 4000T?
Try finding out what the power output for a Zorro slot is supposed to be and hooking a voltmeter up to it (see how to do so) and verifying it's putting out what it needs to.
If the PSU is flaky you can send it to Ray Carlsen for repair. He will be repairing my 3000T PSU shortly.
