I have the same issue. The general error I'm getting is "page not displayed". If I look at my logs all that show are:
Started GET "/auth/facebook" for XX.XX.XX.XX at 2011-05-27 13:49:23 +0000
Started GET "/auth/twitter" for XX.XX.XX.XX at 2011-05-27 13:49:27 +0000
Started GET "/auth/google" for XX.XX.XX.XX at 2011-05-27 13:49:29 +0000
Where XX.XX.XX.XX is my IP address. I just edited it out because I didn't want to post it. It's almost as if the GET request is not receiving any type of callback. Everything tests out fine in the normal browser. In the mobile browser, this is what happens.