Anything I have edited before Feb 8th I don't have an issue with. I can move things around, adjust the slider, cut, split, shift videos with zero delay. Anything after that, including any new files and projects I create tonight, full of delays, lagging, visual error clipping and problems all together. The preview file format now automatically goes to Quicktime with the codec of Apple ProRes 422LT. The project I was working on the day of Feb 8th was automatically set to I-Frame Only Mpeg. This is using the exact same video in two different projects. I have a PC and a rather new one. I recently doubled my RAM as well. This is very frustrating and has already caused my work to take nearly twice as long.