You mention a gate enable - is that to enable the '541?
If this is the case, what happens to the control lines on the lcd when the buffer is not enabled? You may require pulldowns and/or pullups. Also if a keypad is involved, do you have diodes to isolate the keypad?


I frequently run lcds in 4 bit mode and multiplex a keypad with the data lines. The trick is making sure your code is correct and that the keypad does not interfere with the data lines when you are talking to the lcd.