Random lock-up - appear to be screensaver related

I have been getting random lock-ups (usually when the wife wants to use the machine but I have eliminated her as a cause of the problem!!). Using KDE4.04 and once in a week or so (I leave this running 24/7) the machine will not wake from screen off state. No response from keyboard or mouse. I can use ssh to get access to the machine and find that keuphoria.kss is taking up 99% of the cpu. Killing it returns the PC to normal running condition. I found that others have problems with openGL screensavers but their problems appear to occur consistently - any ideas - worth a bug report?

Dave