A few months back I went thru this same thing. I can't remember the model of the adapter I had, but yours sounds hauntingly familiar. As you probably discovered reading the threads, they will make the same model of those adapters using different chips, and to get the right driver you often have to go down to the revs and serial number ranges, etc. Even then I guess there are some adapters that Just Won't Work no matter what you do.
I threw in the towel after a couple of weeks of dicking around with it and got a PCI network adapter. It plugged and played. Not an answer to your question but I thought I would share the painful
experience and my eventual solution.