I'm trying to create a QTVR movie via QTKit, and I've got all the frames in the movie. However, setting the attributes necessary doesn't seem to be having any effect. For example:

NSNumber *val = [NSNumber numberWithBool:YES];
[fMovie setAttribute:val forKey:QTMovieIsInteractiveAttribute];

val = [NSNumber numberWithBool:NO];
[fMovie setAttribute:val forKey:QTMovieIsLinearAttribute];

If I then get the value of these attributes, they come up as NO and YES, respectively. The movie is editable, so I can't understand what I'm doing wrong here. How can I ensure that the attributes will actually change?