Unable to connect to 3G after updating my software I have a Sony Ericsson Xperia X10, and I updated the software to Gingerbread (Android 2.3.3), but I'm having problem connecting my mobile to 3G provided by my Network. When I go to settings and  search for the networks available, it shows that I'm already registered on the network.

Though I have the data access via mobile network enabled, and WCDMA Network Mode, the mobile network state appears Disconnected!
This might not solve the problem, but it is the first thing I would look after:

Many carriers require specific settings in the menu Settings->Wireless and network -> Mobile networks.

Usually when you make a contract, they send you a message with the necessary configuration settings. Updating your phone might reset them or require new settings. If you think that might be the issue, you should have a look around on the website of your network provider. They often publish the necessary settings and/or offer a service to send you a configuration message.

Also, are you sure you need WCDMA? Just asking.