Losing Kontact

I have been using Kontact for 6 months or more and increasingly relying 
on it to "organize my life".  For the period it has been started 
"automatically" as part of Sessions/Start Up Programs" without a problem. 

Until this morning.  Error message reporting that it was already running 
- "started anyway" - nothing happens on screen ... but System Monitor 
shows it to be running and using up virtually all cpu cycles.  So I 
stopped the process.

Started again from terminal, cursors blinks interminably, eventually 
Ctrl-C out.  Started yet again from Applications menu - no apparent 
response.

In Synaptic, re-installed.  No change.  Removed all.  Installed.  No change.

Does anyone have any idea what might be going on, how I can confirm it 
... and, most importantly, how to fix it?

Appreciate any and all help.

Allan