Login/install problem

[anders.hallanger at hjemme.no]

I installed Kubuntu on a laptop over Madrake 10.1. Since I wanted to keep my 
files, the home partition was kept unchanged and mounted as /home. 
 
When I removed the install CD, and the computer restarted, startup of KDE was 
stopped since KDE had no rights to write to my home partition. The reason for 
is was that under Mandrake my uid and gid both were set to 501, while Kubunto 
had assigned a default uid of 1000.  
 
I could enter failsafe mode and reset my uid and gid in the passwd and group 
files to 501. After that startkde cold be run, and sudo used to install the 
programs i wanted. 
 
When I should start up again for a new session, I could only login with 
failsafe, and I am promped for a password when trying to use sudo. 
 
What can I do to resolve this situation? 
 
Anders