Well consider this thread as solved.
I've removed all addons which i have installed since
01/2003 - then i started OFP, checked for the repair truck
and whooop - everything ok.
Then i started adding one after one into the game again.
Everytime i added an addon i started the game and checked
out my repair truck.
Now the weird part: when i added the last addon my repair
truck was still available without having the game crashed
to desktop
However - west side is able to repair their vehicles out in
the battlefield again and CD is happy - maybe a little bit confused now but still happy ;D
~S~ CD