Sounds like you're dealing with Long and McQuade. M-Audio was bought out by Avid a couple of years ago.

What you might consider would be something like this:

http://www.pgmusic.com/ua1g.htm

and a mixer like this:

http://www.long-mcquade.com/products/258...2_Bus_Mixer.htm

This will give you a USB I/O device and a mixer where you can add your mic and your guitar input. You won't be able to record two different tracks at the same time, but you wouldn't be able to do that with the 4X4 anyway, unless one of your inputs is the S/PDIF input.

Good lucky in figuring this all out.

Gary

I'm blessed watching God do what He does best. I've had a few rough years, and I'm still not back to where I want to be, but I'm on the way and things are looking far better now than what they were!