Thanks for your reply rajib.

I've since moved on to Knoppix 7.4.2 and no longer have this problem.

It's good that you've made this note for some Knoppixers that must
use 7.2 for one reason or another, such as graphics driver availability.

My graphics are plain old Intel as you can see:
Code:
knoppix@Microknoppix:~$ inxi -G
Graphics:  Card: Intel Mobile 4 Series Integrated Graphics Controller
           Display Server: X.Org 1.16.0 drivers: intel (unloaded: fbdev,vesa)
           Resolution: [email protected]
           GLX Renderer: Mesa DRI Mobile Intel GM45 Express x86/MMX/SSE2
           GLX Version: 2.1 Mesa 10.2.4
Best Regards.