List box on GUI re-set after "apply" executed?

To all,

I have a created a test GUI using the Block UI Styler and it contains 2 listboxes. When I execute the program (pressing 'Apply') it is executed and work as intended. I have however noticed that the 2 listboxes "shrink" after each execution so after 2 or 3 successive running of the program the listbox is 1 line high. Not very useful! I need to close and re-open the GUI to re-set as wanted.

I initialise the GUIY as follows


Public Sub initialize_cb()
'all the declaratin stuff, etc
LBoxRespSimAndEventName.Height = 6

End Sub


and I cannot figure out where to put a line of code to "force" or prevent the height to change.
Any hint or suggestions?

Thanks
Regards
JXB