hmmmm I wonder why you have script editor issues? I myself use Fedora 7, Fedora 8 and CentOS 5.2 and I have no problems running mirc or using its scripts editor. Check to make sure your graphics libs are updated and you are using the correct drivers. hmmm thought ....I wonder if its the KDE GUI ? Thats native to Ubuntu isnt it?
Anyhow this is a mirc forum not a *nix forum so good luck