380-0299-06 and earlier would make up the bad batch (well, -05 and -06 seemed to be better than the -03 and -04 revisions). 380-0428-xx models should also be okay. The really early models -- the 380-0299-03s with the tan labels -- were the worst (these came out back in late 1999 and early 2000). But they should all be dead by now. Probably even the rest. If you bought something that still works at this point you are probably okay. Post the model numbers (the P/N on the label on the left hand side if looking at the unit from the front) if you want.