When I first started using OSX I found my Serial to USB Adapter was only semi working. I had an old adapter that was no longer supported and I figured it was a waste of time an effort to mess with it. For grins I tried the old adapter with OSX 10.2.3 and it works perfect. I now realize the bug may have been in the 10.1 OSX OS rather than with the adpater. The adapter is working perfect now and even the old software for my terminal node controller (TNC) works in the classic mode. It used to crash big time under OSX 10.1xx