plasma-desktop has taken over my computer

[Claude Jones]

The machine has beome barely responsive; things like the kickstart menu 
button, or right-click on the desktop, or clicking on the options button 
on the panel produce no effect - nothing. I don't remember doing 
anything in particular that could have caused this. If I run top, it 
says that plasma-desktop is using 100% of my CPU. If I long in as a 
different user, the problem's not there, so this specific to my regular 
user configuration. I notice that there are also three processes called 
'migration' running - could those have anything to do with this problem? 
None of them seem to be using any measurable CPU resources...

-- 
Claude Jones
Brunswick, MD, USA