I'm just guessing here as I had a projector that had the same problem. The proj. was Sim2 300. When I made the change you refer to; I had the same result. I believe it to be the scanning frequency---Something to do with not recognizing the dif between film based 24 frames per sec. material/ and 30 frames-- material. I sold my projector. My now 1 year-old Mits CRT tv "blinks" a lot but has always made the change. You might look through the manual and see if there is some "auto-select" mode. Beyond that,call your MFG. I hope you get the problem addressed.