I can't run any games or programs at 1680x1050 with SLI enabled; the screen is garbled and all glitchy (but is fine at the Desktop). I have two GeForce 8600GT cards running Beta drivers 169.09 (I rolled back from the most recent in hopes that it would resolve the issue). The monitor is an Acer AL2016W which I just got today, and I'm very disappointed that I get these issues.

There's nothing that appears in lower resolutions, and if I have SLI disabled it looks just fine. Are there any workarounds, is this just a fault of the cards, or is it something different?

Any help will be greatly appreciated!

It might just be the bad drivers. SLI and Crossfire have been known for bad drivers. You might be able to find a workaround (until new drivers are released), but I don't know of any, sorry.

I did in fact find a workaround. I had to change the frame timing on my graphics card to slightly lower, to "reduce flickering." Everything's working great - I just hope for other people having this problem know how to set a custom resolution@