Do you have sound working otherwise?

First check kmix, it defaults all volume settings to 0. You will need at least master & PCM turned up. Next go to KDE control center & make sure sound system is enabled. Might as well turn on event sounds while you are there. Next check file:/home/crashedagain/.kde/share/config/knotifyrc, set all settings to true. Go to konqueror->settings->configure konqueror->plugins->netscape plugins->plugins & set 'use artsdsp to pipe plugins sounds' checkbox "on". You will also need xmms-arts plugin & configure xmms to output to it.

I think with most recent versions of mplayer nearly all the codecs normally required ar included in the 'w32codecs' package. Not sure if this includes what it needs for DVD though, don't have a DVD drive yet (installing it tomorrow).

I have never seen a 'dependencies will be deleted' message; apt-get usually lists everything it is going to delete so it can be checked before it happens.