Another few tests found the problem. If I un-check the auto complete in the drop down list option for the field then the menu displays correctly. This behavior should not happen so I will be filing a bug report on this problem.
Filemaker 12 Advanced
Mac osx 10.8.5
This is considered expected behavior for you value list. Others have previously reported it and that's the response that they got from FileMaker Inc as I recall. It's a new behavior found only in FileMaker 12.
As I added o another post.... This behavior is very inconsistent. It does not seem to be related to the number of items in a list or anything else. That's he definition of a bug IMHO.
This behavior is very inconsistent.
If it is inconsistent, then it should be reported of course. I haven't personally investigated this, but it's been my understanding that this is a factor of having two things: a value list exceeding a specific length and auto-complete being specified for the value list. If you are seeing inconsistencies when auto-complete is specified, then by all means please report it!