Hello,
I ran your program in CVI 5.5, but was not able to reproduce the problem. The ring control did not go back "up" right after I clicked it to see the drop-down list; it goes up only after you click an item in the ring control. If you would like to discuss this issue further, please go to www.ni.com\ask to create an email support request, and mention my name there.
Mika Fukuchi
Application Engineer
National Instruments