After a week in use I can say that this latest, and likely last, IOpener BIOS rocks. I was used to several USB related crashes per session but no longer. This is a true must have for any and all IO owners. Even MS's USB Internet Connection Sharing works now. Quite a time saver when you need to update Windows.
For the newbies:
The added features in this BIOS are not listed that I could find. Among them are boot from CDROM, delete key enables BIOS edit mode with the stock keyboard (!!) and of course the great USB fix.
Also, my K6 likes it just fine. Boots at 300MHZ without a burp.
Thanks to all who contributed to this hack.