I've figured out why the 8051 can't communicate with the phone at times, it's a problem at the phone side, easily fixed but I still cannot figure out why the LCD will not initialise (or any code after that execute) some of the time. It's not incredibly important because it is something i can easily get around by inserting a tristate buffer between the 8051 and the phone but if anybody knows it would satisfy my curiosity.

Thanks,
Ray