Hi, I'm having the same problem. I can use the tty1-6 normally. My keyboard y running fine into KDE, but I can't neither use a shell with konsole nor using "Run command...". If I login as root and run KDE then I can use konsole. I think it's something with the PATH because if logged as my normal user I try to change the date&time for example, and the WM ask me for the root password then it give me an error saying: "The command 'su' is not in your PATH".. but it is!!! I can SU from a tty1-6.
Thanks, i'm working on it, if I find something I'll write it here.