Major f***up...

I was trying to install the kdipim package and it failed on dependencies, one of which it said was libc6, so I got it and installed it (I'm running Knoppix from the hard drive) and it downgraded the version I had. Since that unbelievably stupid error, the su module isn't recognized anymore, meaning I can no longer gain root on the machine, which means I'm screwed, I can't install anything at all now. I hope I don't have to do a reinstall, does anyone know a way to fix this?

You can use a LiveCD and mount your partitions, then use chroot to gain access. After that you just need to fix what you messed up.