when you fill a combo box it will make selections and if you have code in CmbTruckTyp.selectedindexchanged or any of those it will run that code

when you bind data to a combox i find it necessary to have a boolean called something like initilising. make it true before you bind it and then false when its bound, then in the CmbTruckTyp.anythingchanged you'll want something like

Code:
if initilising = true then exit sub
this will stop code being run before you want it to

Ian