I'm sure sorry about your troubles. Are you using a generic or otherwise odd keyboard? I have an older ATI card on my 32-bit machine that seems to have finally integrated properly into the system (although it took a fresh install to make that happen
Again, I might suggest doing a fresh
install of the MATE
edition (not just MATE on top op Cinnamon), I've heard of some issues with Cinnamon lately - I guess since that fork is of a more cutting edge and unstable desktop (Gnome 3.X) there is a lot more to go wrong. I never could get Cinnamon with Mint 12 (or Gnome 3 with Ubuntu Oneiric and Precise, for that matter) to load properly on my 32-bit machine, even after upgrading to 1GB RAM.
Dell Dimension 4600i, nVidia GeForce 6300, 4 GB RAM, Linux Mint 13 32-bit, MATE edition
Dell Latitude D400, Intel Graphics, 1 GB RAM, Linux Mint 13 32-bit, MATE edition
Gateway DX4860, Sapphire Radeon HD 5450, 8 GB RAM, Linux Mint 13 64-bit, MATE edition