Hmm I leave everything running when i do a burn, I even surf the net, and often open and close other programs whilst burning! But I only ever burn movies at 4x never any faster! I also use AnyDVD and CloneDVD2 but I also save the files to folders (just like Tyler mentioned above) and when CloneDVD2 asks to swap the disk for a blank disk, I cancel out of CloneDVD2 and do the actual writing with Nero. I used to have the occaisonal problem with playback when I used CloneDVD to write. But since I changed to the method I now use I have never had a playback problem! And all this whilst I continue to use my system whilst reading and writing the movie!