Thanks for help removing Perian file
 

Just to say thanks to Colin for all the help. I've a HMC 154 and had trouble with 'smearing' on 720 25p and 50p files, not others. I had 'trashed' perian many months ago and could not find it using spotlight. After many hours of work Colin found it hiding! : Library QT Perian component Unix exec file and another- AC3 file. Once deleted everything working fine
So thanks guys
Happy bunny!