I dunno how to use the "Faster Application Manager".

Use the "Fastest Application Manager" and see what happens...

Become root first... There are many many ways, see which one works for you... If none did, let me know. You must open xterm first, and then try one of these commands. See which one will work, and will make you root:
root
sudo -i

After that, use this command to remove the package you want:
apt-get remove [PACKAGE]

You can try this for installing:
apt-get install [PACKAGE]

If you are interested, see the man page:
http://man.cx/apt-get

This way, you can use the package manager, without stupid GUI front-ends...

You can see how "deep" the problem is, this way... I think there is no problem with dpkg here...

If this doesn't work, it means that we should fix your Debian package manager...