Celstar 8 Delux guiding problems

I own a Celestron Celstar 8 Deluxe Schmidt-Cassegrain. While trying my hand at prime focus photography, I've noticed my telescope periodically will not respond to the hand controller when I'm trying to slew the telescope West. It works fine going East. A friend said this may be due to something I believe he called "backlash". Does anyone have advice on how I can correct this problem? I'd appreciate your advice.