Get query string for root URL

[maq]

Hi,

I am writing a GAE/GWT application and trying to set up the SEO/crawler handling, so that :
            http://xxx.appspot.com/?_escaped_fragment_=PageName
can be caught in the filter , in order to serve the cached GWT pages.

However, the filter  doesn't seem to be catching the request,even though it sets to url-pattern as /*

Does anyone have a suggest for this? GWT/GAE/SEO should work :-)

Thanks!

maq