Thanks a lot! For anyone interested: It turns out that the sub-VIs that were loaded, resided in another version of my application. Oops! After a reorganization of our group's folders, LV could not find the sub-VIs on the supposed location and therefore started to look in its search paths. Since the sub-VI was in a neighboring folder to the top-VI, not one folder below, the <topvi>\* search path was no success. Instead, in <vilib>\* there existed a sub-VI with identical name but different behavior. This took some time to figure out.
By the way, I think Labview could improve somewhat in the way it manages software projects. /Andreas
