Not immediately. Haven't heard of that issue yet.
Can you try setting up the Request to *not* use the Breakout Canvas setting? That should just go to your standard App Canvas URL (
apps.facebook.com/your-canvas). See where that goes.
My only guess is that this isn't really related to JFBConnect, and is more of a template switcher issue for your mobile template. Not sure if you have one, but if it tries to do some redirections for mobile views, that may somehow be interfering with JFBConnect.
Let us know if any of that rings a bell!
Alex