Lantau, great phone but sometimes it hangs and you need to remove & reinstall
the battery before you can start it again. Glitch in the software ...
I got the software updated at the service centre FOC and it works great now.
Check if the software is the latest version (if you can). The svc centre deletes
all inputs and settings so it might be worthwhile to do it asap to save you
installing and setting things all over again.