Hi craesz,
hmm, if you can't install a rpm then there is definitely something wrong. The output in your last post about the charset not found for en_US is strange. Looks like an incomplete/interrupted addlocale run when localizing the system? Can you run addlocale and rest to en_US, then reboot, and see if you still get that error when running the xterm command? If not, try to install the rpms or run lomanager again to see what happens. Or maybe you have a partially updated system due to the repo problems right now? Reinstall is of course an option, only takes 5 minutes; lomanager should run without problems on a fresh reinstall, it only pulls in rpms from LO, so you don't even need our repos, just an Internet connection / or the set of LO-rpms.
good luck,
-p.