mod rewrite question

I'm hoping I can get an answer to one of the 4 questions I've posted to this
group over the last couple of months, so here goes.

I'm serving XHTML files as application/xhtml+xml as they should be. But IE
doesn't like this. What I wanted to do was use mod_rewrite to change the MIME
type to text/html for IE. I thought I could check for .html at the end of the
request and then use $1 to put the filename back in. No luck though. If
anyone has any thoughts, or a different method of doing this, it would be
appreciated!

Here is httpd_conf

RewriteCond %{HTTP_USER_AGENT} \bMSIE
RewriteRule .*\.html$ $1\.html [T=text/html]


And here are the relevant bits of rewrite_log

init rewrite engine with requested uri /cv/index.html
applying pattern '.*\.html$' to uri '/cv/index.html'
RewriteCond: input='Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)'
pattern='\bMSIE' => matched
rewrite /cv/index.html -> .html
remember .html to have MIME-type 'text/html'
local path result: .html
init rewrite engine with requested uri /cv/index.html.var
applying pattern '.*\.html$' to uri '/cv/index.html.var'
pass through /cv/index.html.var

----
Michael Newton
http://mike.rancidcrab.com