Request.Querystring == null from inside Iframe

Request.Querystring == null from inside Iframe

I have a simple mvc page that is being loaded in an iframe on a tab of the
account record in dynamics crm, set to pass the parameters through.
this works fine, the page loads and if I right-click - properties, I get
the url+parameters as expected e.g. -
http://myserver.com/?type=1&typename=account&id={816E90BE-7DBC-DD11-9E0B-001C25CFAE82}&orgname=MyOrg&userlcid=1033&orglcid=1033
However, in the controller I have
Request.QueryString["id"]
and this returns null, also Request.QueryString is null
If I load the page in a browser without the iframe
Request.QueryString["id"] has the guid as expected.
What stupid thing have I missed?