Video apps going CRAZY

Ok so i installed VLC the other day and it worked perfectly. today I try and use it and it just bounces once in the dock and then stops. doesn't launch doesn't tell me anything. I then download mplayer, same thing, bounces once and then doesnt do anything. Finally I download the divx plugin for quicktime in order to use that. the installed just tells me an error occurred and i should try to install again. no matter how many times i try it keeps doing it. help!

General apps advice

When apps act up, a few things often help.
Delete Preferences files for the apps from your library.
Zap the PRAM, by holding down Cmd/Option P and R right after choosing to restart and hold them down until you hear the startup chime a total of three times.
Sometimes just a restart by itself helps.
Also always, after installing any software, Rebuild Permissions using Disk Utility.
FWIW

Frank

Find and delete the file:

org.videolan.vlc.plist