How to change the network roam to manual on a Windows Mobile
From the home screen press Start and then select Phone.
Select the Menu at the bottom of the screen, and then Options.
Select the Network tab from the bottom of the screen.
In the Network selection drop down select Manual. It will automatically start searching for all available networks.
When prompted select the network you wish to connect to (you will only be able to select your home network while in the UK). Once complete you will return to the network tab. Click OK to return to the home screen.