OK, I got my cable and gave this a try. When I open INPA, the battery and ignition lights are white (not black). I know this means some sort of communication problem, but I think I have everything correct.
My device is on COM18. I updated obd.ini in C:\EDIABAS\BIN and in C:\Windows. I saw there was another one directly in C:\, is that normal?
I got the drivers installed that were from LTDI (or whatever it was). I added a semi-colon + C:\EDIABAS\BIN to the end of my PATH and defined the new variable (and rebooted).
Any other common things I could be missing? I am not really computer unsavy, the instructions seemed pretty easy to follow.