simple rewrite rule produces 404

[tomfmason]

This should be rather simple but I am starting to find out that it is not so simple.

I am trying to basically create a reverse proxy with mod_rewrite.

Here is the rule in question.

[code]
RewriteEngine  On
RewriteRule ^images/(.*)$  http://static.mydomain.com/images/$1  [P]
[/code]

When I try this on this on the server I get a 404 error.

Any suggestions as to what I am doing wrong would be great.

Thanks,
Tom