I finally bit the bullet and removed USB Overdrive, using its uninstaller. I've gone over a week now without the problem occurring, so USBO has to be the issue. Should have done it sooner, but I got used to simply unplugging and replugging the USB connector to fix it.
Next I will make sure every remnant of USBO is gone from my Mac, so no pref or settings files are hanging around to cause issues. Then I'll download and reinstall the latest version (currently 3.2), and configure it from scratch. I'll run it for a few days, and post back here to everyone know how it goes.
If the problem reoccurs, I'll contact the developer to let him know and offer to provide any help I can. If I remember correctly, his is quite responsive.
Thanks for the help so far.
