If you pre-enhance a select it gets double enhanced. We should protect against double enhancement and/or honor the data-enhanced attribute.
select: Honor data-enhanced="true"
this is something for 1.5 providing pre-enhanced markup is not an option in 1.4 see http://api.jquerymobile.com/selectmenu/ This option was only added to some widgets in 1.4.
Closing as duplicate of #6546