As the post above said, the OS on your PC is probably your problem. Which OS are you using? WinXP, Win7? I can't for the life of me get Windows7 to recognize my ICS Gtablet but o'well!
If you are comfortable with using or trying Linux, you could try installing Knoppix on a USB drive and run that. I think Knoppix has everything set up for MTP & ADB already and is 'live' so no real configuration is needed to get it running (except for your wifi of course). Just use the Linux version included in most NvFlash packages. If you have a fairly powerful computer, you could also try running Linux in a VM, but Knoppix doesn't run in a VM very well.
My favorite is Arch Linux (not in a VM). Although you have to build and configure the system yourself from the ground up. Since I started using Linux I have really enjoyed it. It is much faster than Windows, more secure and gives me less problems than the Win PCs I deal with. Check out this site if you are interested in Linux.
To top on this excellent information. If you decided to try a Linux disto I would recommend a version of Ubuntu, doesn't really matter which one they are all really user friendly and depending on you pc setup depends on which version of it you can use. I have 11.05 installed on a 2nd partition for doing my Droid stuff on a computer that is around 9 years old, runs smooth. Windows xp is the other alternative which I have used several times NVflashing stuff, but adb seems to run better through Linux in my opinion.