This legacy browser behavior is frustrating in the extreme.  Why in heaven's name would a tool meant primarily for viewing HTML, request XML as a higher quality representation?  Just goes to show how uber-excited everybody was about XML once upon a time.  You know, because in the future, all web pages will someday be XML with a reference to an XSL stylesheet, not HTML.

Choosing a different MediaType for your XML, that the browser doesn't ask for, is the usual solution.

Another workable solution I have found -- if you are using XML and will get criticized for making up MIME types -- is to expose the browser-friendly HTML variant by itself on a distinct URI (e.g. person.html).  That's sloppy too, just in a different way.

Now, packaging your data with JSON instead of XML will avoid the issue altogether, without making up MIME types  =)

- R