My 9810 just bricked today. I got it going again and loaded ATT 7.0.0.583.
I noticed that the loaded App World was an old version after I used it to reinstall a bunch of apps. So I upgraded App World too.
When I try to go into "My World" or download any app I get "An error has occurred. Please try again later. (Error Id: 40850)"
I poked around online and see some people saying that it's a clock/time zone issue or a wifi issue. My clock is automatically updated and date/time/time zone are correct. This occurs whether on wifi or not.
I tried deleting and reinstalling App World both OTA and via BDS. I am in the same place I started from.