Register -- copy one userfield to another problem

[johnmont]

When someone registers I'm copying the data from one userfield to another when they submit their registration information.

PHP Code:

Hook Location : register_addmember_process

$vbulletin->GPC['userfield']['field16']=$vbulletin->GPC['field12'];
$userdata->set_userfields($vbulletin->GPC['userfield'], true, 'admin'); 

This worked great until I changed one of my userfields -- the one for Country -- from a text entry to a single item popup menu listing of countries. Now, whenever someone submits their Registration they get an error message the required "Country" has no data....even though it was submitted. For some reason, there is a difference between using a text input field for this vs. the select menu.

Is there a way I can do this? I'm a bit lost....