Falle,
I would classify pushing a button on my remote (if it's available) and having the problem corrected a "fix". For example, as I originally stated, I see similar behavior in switching between HD and non-HD channels. If I have the aspect ration set to wide for HD, then switch to non-HD, everything is stretched until I set the aspect back to auto. I suppose opinions vary as to whether changing the aspect ratio is a "fix" or a "workaround" but I'll take it either way. That's my personal opinion. In any case I wasn't pushing it as a fix here, just trying to gather information on the problem.
Jason