Uhh... do as it says? That is, run `dpkg --configure -a' again.
If that results in an error, post the complete output. Otherwise, if that for some reason doesn't work,
- Find the name of the package you want to uninstall.
- run "apt-get remove <name>" or "apt-get remove --purge <name>" as root.
- If that doesn't work, the post everything spewed out onto the console, from (including) the apt-get remove command up until (including) you get a prompt again.
In that way, we'll have something to work with. Best of luck --Jonas