I've just been there!
When this happens it is because there are dependencies on other files which you don't have access to as you are on the
stable distribution. Youll encounter a lot of this.
Only one way out. Go bleeding edge. Add unstable, testing and experimental to your sources.
Frankly I've had little or no problems in doing this except once, a few days ago when KDE Control Centre would not respond to the admin password. This was fixed the next day with some new files.
One thing to note, when you go this way there are up to 70 updates every 2 days or so.
If you decide to do this here are the sources I use. They work. Add them to your /etc/apt/sources.list and then update. Update everything non-KDE first, then go KDE.
FWIIW I use Synaptic Package Manager for all this. It is easier than Aptitude.
Warning: Your mileage may vary. All I can say is that it worked very well for me and this is in fact why I have switched from Mandrake. I have some problems but none seem to be related to being on the bleeding edge. They were there from the start.
OK, all that over, here are my sources. Note there are lots of others, See the pinned post at the begining of the Debian Forum.
Apart fom the DVD sources I have: