I am seeing this same error message with the same configuration. I have systems running 5.5.3 on the same Isis, which have never reported this error. Seems to be specific to MC 6.0.1 on OS 10.7.2 with Isis 5000. I just spoke with Avid about this problem and will relay any information they have. Let me know if you have found any solutions on your end.
Thanks