Mobile Joomla doesn't respect Site Offline setting

I have a site running Joomla 1.7.0. Currently just using the default Joomla template and the default Mobile Joomla template. I have set the site to be off-line using the Joomla control panel. When I access the site using my desktop PC, the site shows the standard off-line message. When I access the site using my Blackberry Torch, the site comes up in the Mobile Joomla template.

Is this a bug, unimplemented feature, or did I miss a setting somewhere.

Thanks

Offline mode works correctly on our J!1.7-based test site. So, seems there two possible solution:
1. You are logged in as admin on the phone.
2. Joomla responses with "503 Service Temporarily Unavailable" http status in offline mode, and it maybe that the phone displays cached content in this situation.