When creating a render url, we are leaving out the normal windows state property from the url in an attempt to simplify the url (assume that the normal mode is the default mode and therefore doesn't necessarily need to be specified in the url).
There appears to be some issues with the integration through. Parts of the portal code itself seems to be setup to assume that no window state means that the window state shouldn't change from the current windowState. This is causing some issues.
The remote portlet will not return the parent window back to the normal mode because of this.