I have implemented Darrel's suggestions and they improve the situation but do not fix it. The LCD now starts about 50% of the time - up from less than 10% - but still not a solid solution.

I think the problem lies (in part) in the power supply dV/dT at startup. Depending where in the mains cycle the unit is turned on, the power rise time can be from 20 - 90 mSecs. The data sheet implies the rise time should be under 10 mSecs and if that cannot be guaranteed, then a software reset sequence should be followed.

Does anyone know the software sequence for 4 bit mode? The only examples I can find are both ambiguous and written for 8 bit mode which I cannot implement on this existing PCB with all i/o pins used on the PIC16F877A.

Cheers
Brian