Whoever told you to uninstall the old drivers first was the one that did you bad!
The omega drivers build on your default drivers set for your video card, they are not a replacement, but an enhancement..
The only way to get a successful install of the omega drivers is to install the set up file, then once you have them installed, go to your device manager, then display adapter tab, right click your video card then click properties, then the driver tab, once you get there, click update driver, then click "have disk" and choose the location where the omega dirvers were installed and proceed. The driver will pop up a warning that the driver is unsigned, ignore this and proceed.
What messed you up 68 was uninstalling your default drivers, this causes the equivilent a nuclear meltdown. Once you get everything installed it should be fine, just make sure you dont fug around with your old drivers, that was a piece of bad advice, the omega drivers are meant to be an enhancement, not a replacement. If you have any questions make sure you follow the directions that come with the Omega drivers to the letter!
The difference it makes is amazing!
Also, in regards to the vsync option, apparently it causes some problems if you change it form what it is set at, I had to reinstall AH2 today (80meg download on a 56k is like dying) as AH2 wouldn't run once I changed the vsync settings, either way I set it. Not sure why though...