F12 Not Working Since Dreamweaver 8 Install

My computer had Dreamweaver MX 2004. IT installed Studio 8, thinking it was an
upgrade and it was not. Since then, when I press F12 to preview a XML file, it
fails to bring it up in IE6. We tried uninstalling both MX 2004 and Studio 8
then reinstalled Studio 8, no difference. I tried removing and reconnecting to
IE6 through the Preview Browser preferences, same thing. If I have an HTML
file open and press F12, no problem. Just seems to be happening with XML
files. Any help would be GREATLY appreciated as we are in the middle of a
large XML conversion project.

Ken Roberts
San Antonio, TX