not seeing your issue, I am using Hosie Wilkie set, seems ok, I have been able to watch cloud formations slide on by, however I do occasionally get a large redraw of clouds, would like to know if there is a setting to change this? I fault the RWC setting not to change visiable clouds was for that but I may be wrong....done around 8 lights in 4.6 now and for me at least performance has improved on 4.5 , however all PC's are so different along with each persons XP setup....