Have you downloaded the SuSE multimedia packs? SuSE by default ships with a lot of the multimedia stuff turned off. You need to install the optional multimedia pack patches to enable them. This can be done via YOU (YaST Online Update). Once you have this done, you might want to go "whole hog" and install all the other multimedia "enablers" out there.
I found (as have numerous others) that after I had installed all of the multimedia option packs, SuSE would play .mpg and .mp3 files, but no joy on my .avi and .wmv files. I searched on the web and found that there is a site in Germany, where someone has rebuilt the relevant packages from scratch, not from "crippled source" like SuSE did. If you delete your offending media players, add this site to your list of installation sources and then re-install, all is well. This is what I did, and it worked great.
Here is the "recipe":
1) Go to YaST, Software, Change Source of Installation. Select Add, then select HTTP from the drop down list
2) Add "packman.iu-bremen.de" as the server, suse/9.3 as the directory
3) Finish out of Change Source of Installation
4) Go to YaST Install and Remove Software
5) Delete (uninstall) Kaffeine, xine-lib, xine-ui
6) Install the following (Search for each one by full or partial title and then select):
7) Finish out of installing the software and then reboot
This fully resolved my issues with SuSE 9.3's multimedia limitations. I hope it helps you!