http://www.quirksmode.org/bugreports/archives/safari/index.html "When loading XML through XMLHttpRequest, the resulting DOM does not allow access to content of elements, which happen to have the same element name in html AND which have an empty content model in html. Example: the <link>...</link> element from various RSS flavors is not available in Safari, using DOM methods, because an empty <link/> element is defined for html. Test page http://www.xs4all.nl/~jlpoutre/BoT/Javascript/RSSpanel/safari-testcase.html Workaround is not included Reported by: Johannes la Poutr�."
I cannot reproduce this, and the test page actually says that this has been fixed in Safari 1.3/2.0.
Closing as worksforme, as i see the same as AP.