Since then (after rooting the phone with CF auto root - don't think this has anything to to with the problem) I have noticed that at the times my phone won't send texts, in the setting pull down section it shows no signal whilst still showing signal in the notification bar. I have also noticed that mobile standby uses a large proportion of my battery.
I will upload screen shots from my phone soon.
The only thing I could think of that might be causing it is that the SIM card I'm using has been cut down from normal size to micro size.
I just wondered if anyone know's what's wrong or could suggest any fixes?