For me, whatever changes happened to dynamic in 2.7.6 have made it work poorly again. It is back to being really unresponsive to lowering when I am using the gpu for other things. It will lower one intensity or even stay the same as when I am not using the gpu for something else. I am on Windows 7 with two 5870s. What specifically changed with the algorithm in 2.7.6?

(2.7.5 is running smooth, and responds quickly when other programs use the gpu, and all I have to do on that version is set the intensity to fixed then back to dynamic and I never get the negative intensity bug anymore. 2.7.5 is the first version since 2.1.2 that I can get high performance when not using the gpu for other things and still have really responsive backing off of intensity when I do).