[CS-FSLUG] File associations brocken in KDE (Mandrake)

[N. Thompson]

When I first installed Mandrake 10.0 there were no file associations for .pro 
files, they are project  files created by Qt-Designer and Qt-Designer is the 
only program I know of in Linux that can actually make use of the files. I 
set up a file association type called x-pro following the naming scheme that 
seemed to be in use and I set Qt-Designer as the default application for 
opening these files. Every time I reboot KDE forgets these settings and goes 
back to trying to open them with KWrite or KDevelop and the association with 
Qt-Designer isn't even available in the right click menu any more.

Is there some reason why KDE would be forgetting the file association, how do 
I work around that?