Corrected entry: General problem with the camera technique. They did not "sync" the movie camera with the television and computer screens in the movie. When the camera is out of sync with screens that are being filmed, it causes a distortion band across the picture tube. Two of the scenes where this is extremely evident (and a bit annoying) are when Roger and Johnny are watching the Stillson commercial and when Chris is on the computer (very visible green flickering band across the computer screen). Modern digital video cameras use a program called synchroscan to synchronize the camera to the TV screen being filmed.
JC Fernandez
8th Aug 2008
Correction: Limitations in the technology at the time of filming are not mistakes.
JC Fernandez