Url params in routes

[eluser]louis w[/eluser]
I have the following route set up:

Code:

$route['XML/foo(.*)']      = "foo$1?format=xml";

The route works, but errors. It seems like the re-routed uri becomes

/foo/bar?format=xml/

Notice the trailing slash. Is there a way to have url params work in routes?

Thanks.