"Illegal URL format"

The general flow of Facebook Connect is:
* User clicks the blue button
*** JFBConnect sends some information to Facebook via a URL (where to return to when registration is complete, permissions required, etc).
* User logs in in on Facebook.com
* Facebook redirects the user back to your site with the funky URL above (this is the URL being denied)
*** This URL contains a "Session Key"
*** The "Session Key" is then sent back to Facebook for verification, along with some other info via Facebook's PHP libraries. This is all done via cURL requests from your server (not through the browser)
* Facebook verifies the session key and that your FB Connect application is 'valid'
*** Facebook gives an Authorization key which we store for the duration of the session to keep the user logged into your site.

Little overkill to explain it all, and there are many big pieces left out. Either way, the important things to note are:
* The URL being denied is sent from Facebook.com directly, and there is no file on your site we can edit to change this
* If you were to try to modify the URL (use htaccess to strip excess //'s, let's say), the Facebook library probably wouldn't be able to retrieve the Session Key properly and eventually get an Authorization key.

So, in short, no there's nothing we can do on our end that I can think of. Hope this helps explain our end a bit better. We can answer questions all day, so if you have more information from your provider, or just curious about something, let us know.

Awesome! Thanks so much for the review, we definitely appreciate it.

We also want to get you going, so stay in touch and let us know if you figure anything out or hear something from the security provider. We'll help however we can.