In some cases, if an item with a string name of length greater than 6
characters is added to a choice list, the choice list rectangle gets drawn
with the right edge missing.

This happens, for instance, if the word "caterpi" is the longest word
added to a choice list.
If, however, the word "caterp" is used instead, the choice list box
gets drawn with all 4 edges.

The attached applet can be used to recreate this scenario.