So I put a new tube in the tyre, and this time pumped up to 65psi. Everything seems ok. Just did 20miles and no explosions. The road definitely feels rougher with the higher pressure though. I'll give it a few days and see how it goes.

Mimi - I suppose the pump could be faulty, but I hope not. It is brand new after all. maybe I should head in to the lbs and have them check the tyre pressure just in case.