vauxhall corsa 1.2 twinport door problem?

my wife bought a vauxhall corsa from a garage in january, they thought there was something wrong with the engine when she bought it because it was misfiring so they had it re-mapped and supplied a new ignition key,the key opens the passenger door and drivers door but wont open the boot of the car why is this???? the timing belt was the problem

stewart
December 2010