Unable to checkmark an OPTION menu menuitem on Mac OSX

[rfarnold]

I can add a checkmark or other mark to pull down menus but not option menus. The documentation seems to suggest that I should be able to do this. It cites a different option menu exception for Windows, but none for Mac OSX. Is this a bug, an exception not mentioned in the documentation, or am I doing something wrong (by putting "!c" in front of the menuitem)? Thanks for any help. I would really like to add this feature to a current project.

Bob Arnold