:) glad it helped at least a bit :P
I don't know what you can try to re-register next. I think only the codecs needed for the playback of that specific file, but I doubt the result will be better then now.. but it's no harm to try
I think you have to check first which filter is really used by BSplayer when decoding the movie.
Once you open the file right-click on BSplayer window -> Options -> Filters -> Advanced
There you can see the filters actually used by the player. Probably you'll have to reinstall them, or change the decoder used to play that file. It depends from the filter used.
Maybe it's not a codec problem, maybe your antivirus uses CPU to unpack and chec BSplayer..I don't know..
Have you checked which process really uses so heavily your CPU? BSplayer is known to be low on CPU usage and memory load.