Thank you for your post, and I apologize for the late reply.
This is the way it should work. Other users had reported that the import mapping was ignored in previous versions, and it was fixed in FileMaker Pro 11.
Thanks for getting to this and confirming that this was a decsiion at Filemaker to change the behavior. I would like to point out that this change in behavior was not specified anywhere that i could find online at Filemaker or the net. Please, please, please get back to development that when you change something like this, weather considered a bug fix or an enhancement, you really have to document it in the changes. Instead of spending lots of time tracking this down would not have been lost if i had seen in the change report in FM 11 that there was a change in how this was handled in XML/XLST import.
On another front, it seems odd that when using XML with or without XLST that you would want to override the fieldname matching of FM fields to XML tagged element data. But then again, i haven't tried to come up with a reason to not. It would be nice to know if the others who reported that it was ignored where complaining because they wanted the capability to not match XML tagged element data to FM fieldnames or just noting it?
In any case, have a happy Solstice today!