I thought this was happening about a month ago, got the receipt ready to take it back - it was bought in April so is only 6 months old. then it seemed to start working again. But yesterday I missed a text at lunchtime despite it being right with me, and later I saw it come on and light up as there was a new text, and it didn't make a sound. I've checked the settings etc, nothing wrong there - and just now it did ring when a message came in.
It's a Sony Ericsson and cost about 80 quid so I think it ought to work properly for more than 6 months - will I be able to take it back do you think/ It was Argos and I'm afraid they'll say 'we have to repair it' or something.