Try setting the preferences for the kterm (I think, I use Eterm, myself). If that doesn't fix it, see:
man <applicationname>
or
info <applicationname>
for any hints.
As a last resort, delete all directories named .kde<anything else> and re-start X.
You will have the default desktop and configs re-generated.
You can usually find the configuration files for something by looking for a file named
.<applicationname>rc
