There is a setting under the Core start menu folder to re register the filter, can you try that and make sure that CoreAVC is set for h.264 in mp config.
Think you have a filter clash in what is being used, you might want to try SAF, keeping the CoreAVC installed, but using the pdvd9 codecs in the unlocked version of SAF, then see if you can switch between them.
I re-installed coreavc, then the movie worked, but then i have this problem in another movie.
Maybe i have to re.install MP because i have an issue with the tv also.
I hav to stop (B) everytime i want to change a channel. If i dont do this MP hangs and i have to use ctrl+alt+del to stop mp, and then i have to start it again.