kontact file dependencies/interactions

I posted a while back about kontact not "visibly" starting and thanks to 
monumental help and patience from one of the list members (who I guess 
should be nameless but you know who you are!) got that issue resolved.  
Re-install and deletion of std.ics seeming to do the needful.

After a few trouble free days lulled me into a false sense of security, 
the problem has now become a bit different.  Over three days I have 
experienced the duplication of every to do, after painstakingly manually 
deleting the dupes then finding on the next start up that there were 
(still - I think not but I may have missed them) 39 duplicated to do's 
and, having deleted them, found on today's third start up that now about 
70% of the to do's have just disappeared.

So if anyone can suggest what's going on there I'd much appreciate it.  
It would be real good to know what's going on and whether the problem(s) 
is(are) occurring on boot up, shut down or while running.

However I have a second issue that is becoming increasingly important 
and frustrating.

Doe anyone know what is the "pecking order" of the files?  That is does 
it make sense to delete the std.ics and std.vcf files and have the 
system replace them?  Or does it make sense just to replace the whole 
kabc and korganizer folders from a hopefully good backup?  Or does it 
make sense to replace the std.vcf's in korganizer from again a hopefully 
good back up?  Or maybe does it make sense to delete all of those and do 
a calendar and address book import? Or what?

Because of the problems I've had I have backups (of all of the above) 
all over the place and, while I seem to see issues with the date 
stamping of the files, it sure would be nice to go the newest "right" 
file and try it.  Then the second newest ... and so on.

Assistance badly needed and muchly appreciated.

Allan