The drivers will definitely work for all nVidia 6/7/8/9xxx chipsets, your's included. The only joy you will get is from using the nvidia driver, not the vesa/nv drivers, this is almost certainly the cause of your problems. Also, it sounds like you have dropped back to UI1. Forget Alpha blending for now, just return to the AV Wizard on your next boot, and choose the medium interface (UI2 with masking). Then carefully follow the instructions in the wiki under Display Drivers on how to download and install the video drivers (try the latest drivers, and also the immediately preceding version of the drivers, just to make sure there are no strange bugs in the latest version).
The other issue, is, it sounds like you have been messing around with configuration in several places without really knowing what you were doing. Its possible you have screwed up some config somewhere you weren't supposed to touch. That could be difficult to fix up. Realistically, the only things you need to touch are 1) the AV Wizard to select the interface and resolution, 2) the nVidia drivers to install, 3) sometimes the xorg.conf file to customise things a bit, 4) very occasionally the nvidia-settings tool, perhaps to set vsync settings.... if you're messing around with anything else, don't unless someone specifically tells you to, or at the very least you keep a very accurate log of exactly what you changed.
Worst case, you may need to reinstall LMCE just to be sure you are back at a known point, otherwise you could be chasing your tail a bit. Either way, the 7600 chipset is perfectly fine, and works well with LMCE (albeit a bit of overkill) as long as you install the newer drivers, and follow the correct setup path.
