[AccessD] Not in List ... or Not?

Hi everyone!  Hope everyone is having a good day.

This may be just the way it is, but I still have to ask.  Access 2003.

I have a combo box, Value List, I typed in the list, Limit to List. 
Default value is set to one of the items in the list.  List cannot be
added to.

My list has four(4) items in it.

So, why can I enter a BLANK in it?  A Blank is NOT one of my items in the
list.  Last time I checked, when one says "limit to list", you should only
be able to put in what's in the list.  Period.  End of sentence.  Nothing
else.  Zip, zero, nada, nothin'.

I know I can check the field on exit to make sure it has something in it
other than a blank (since the limit to list DOESN'T frickin' work right on
blanks...), but I have about a gazillion other events happening with
focusing and it hoses them up when it tries to go back.

Is this just one of those Access quirks or am I missing something?

TIA!

Greg Smith
gregsmith(no spam)@starband.net