Well I can't be of much help concerning a fix but I too have had a few issues with garbled program when trying to edit. Sometime I will get extra blocks at the end of my program that I don't want or simply won't work. When I attempt to delete these the control acts like it will lock up for 10 or so seconds and then it will dump all my tool data and offset pages. The tool file page however will stay intact. Sometimes I have to completely delete the program and resend. Make sure the % is at tht end of the program and is directly after the M30, ex.
Sometimes my CAM software will put a blank line between the 2 and I think this causes problems.
Hope this helps.