Phone: Razr i The difference: Usually locked phones only work with one network, BUT - T-Mobile UK have joined Orange UK and in my list of selectable Networks I can chose either "T-Mobile / Orange" or "T-Mobile". Both work. The issue: My data singal on "Tmobile / Orange" is rubbish, but it seems this is the phones default option and when I select Tmobile it reverts back to Tmobile / Orange around 15 mins later. I need to change the default carrier to Tmobile. I'm thinking there must be an app that could lock it? I'm open to rooting if this will help solve it.