I would suggest you install a simple desktop you're comfortable with, then remove all of GNOME (as much as you know is directly tied to the gnome package). From there, just reinstall GNOME.
But that's a last ditch, and I hope you can find a better way. I have a feeling that by reinstalling GNOME, you may lose a ton of GNOME settings.
Actually, I may have a better idea. Insert your 2.2 disc. Launch Synaptic Package Manager and click "Add CD-ROM," selecting the Mint disk. Then re-install any packages related to GNOME, and go on re-installing until all of your Mint-y features are restored!