Alalbama not displayed in select list for states

I'm using Drupal 4.6.2 with the address module and PHP 5.0.4. For some reason Alabama does not appear in the popup menu of states. As a temporary work-around I disabled this line in the address_build_states function:

array_unshift($states, t('Please choose...'));

So this makes Alabama the default and leaves out the "Please choose" item.

I'm totally stumped by this. Viewing the HTML source shows that Alabama is in there and I don't see any HTML errors. I have tested it on Safari (Mac), Firefox (Mac), and IE 6 (Windows). It seems to be related to having option value="0" selected="selected" as the first item in the select. If I change the above line to $states[0] = 'Please choose', Alabama shows up and the 'Please choose' item is the default (but it is at the bottom of the list instead of the top).