Error: codec search

I am using openSuse11 - kde3.5.
My konqueror give strange error msg saying search for codec whenever there is video file in folder.
I am using mplayer as default. Konq is Ok but kdialog appears with error message about codec search. What should i do?

Do you mean that while browsing with Konq and you have a video file in a particular folder, Konq crashes, what's the error message exactly ?
To me, it sounds like Konq is trying to do a preview of the file, but video playing doesn't work for some reason, can you click on the file and actually watch it ? Do you have some media player installed, like VLC or mplayer ?