Hi all, I bought an Iphone4 for my mum from Celcom (unlocked) like 4 months back and my mum keeps on telling me that it happnes quite often to her that the slide to answer call does not respond when she receives a call. Her description was that she tried to slide to answer the call but the slider will not respond, causing her to miss a lot of calls.

Is this a normal problem? Or should i send it back for warranty to Celcom? Thanks.