Vakue kists in runtime file dragging

[libbystow]

I have a runtime file using two values lists. Depending on which category value is chosen on one list then the other list displays a list of values available for that category. This works fine except I now notice in FM Advanced that the value list appears to drag, usually displaying what looks to be multiple copies of the 2nd value. Of course chosing it makes the copies disappear. I think this must be a screen refresh problem that has just crept into the new version. It certainly never happened in Developer 7. Any ideas how to fix this?