Please start it from console with "kapi" and let me know, what the output is.
How many contacts do you have in KA/Pi?
What resources do you have configured?
Do you have fastload enabled?
After getting the output, please disable fastload, close KA/Pi and other.
Make a backup of your data.
Now rename (HOMEDIR)/kdepim to kdepimbup.
(Use command mv)
Now try to start again.
Let me know, what happens.
Thx,
z.