Pressing CTRL-ESC will bring up the KDE System Guard application. This is as close to Task Manager as you are likely to get, and even has a nice highlight the app and press the [kill] button action. Hope that helps.

Wasn't trying to appear unhelpful in previous post, just imparting a little history/reminescing on some of the problems I had with that particular keystroke combination. ;>

Incidentally I only found out the CTRL-ESC combination by a fluke the other day (I admit to not having looked at the keystroke mappings in Knoppix, I spend most time on the command line). The mouse wasn't working on a server that we were trying to boot Knoppix on, so I started pressing key combinations to see whether I could get to the KDE menu. CTRL-ESC brings up the Win32 program menu so I tried that, and up popped System Guard. ALT-F1 was the combination I really wanted BTW to bring up the KDE menu. Unfortunately my server didn't boot correctly because it needed megaraid.o, guess I'll need to remaster or modprobe it in after the fact.