High CPU usage w/ Firefox 4
 

I've been using my DL adapter on my Mac for a few months without too many issues. Today I noticed a lot of CPU being used by the 'WindowServer' process, which is abnormal. I had a single Firefox 4 window open on my DL display with a dozen or so tabs. Once I move this window off the DL display or just minimize it, the CPU usage for the WindowServer process drops from 50+% to around 2%.

Even a single tab window with the Google home page on it shows similar CPU usage. I'm going to roll back to Firefox 3.6, but I wanted to throw this out and see if anyone had similar issues.

I think I found a solution - Under Firefox -> Preferences -> General there is a 'Use hardware acceleration when available' check box as part of the 'Browsing' category. Turning this off (It is checked as default) and restarting Firefox resolved the high CPU usage by the WindowServer process when you have a Firefox window open on a DL display.

:D