Just Wanted Reassurance
I wasn't trying to cause a debate or sound obstinate, so don't take it personally, this ignorant newbie here only wanted reassurance that it was a problem with the codecs before messing around with installing new codecs, because I know *nothing* about which replacement codecs I will need to install to fix the problem, and I was hesitant to immediately go off willy-nilly trying to find replacement codecs to install (and possibly install the wrong ones and screw everything up) without being certain I had properly diagnosed the cause of my problem. I do very much appreciate your help, and I will find out which codecs are on my machine and try to find a better codec package that will (hopefully) fix this bug. You'll have to forgive my ignorance on the subject; up until now, I've never had to understand anything about codecs in order to view and edit AVCHD video files on my machine, because I've never encountered a problem like this before. Hopefully new codecs will solve the problem, as you have suggested. Thanks again for your help.