Mine stopped functioning near the end of the first summer ('02) I got it, so I just started using a long lighter. But the next spring, I removed the connections, and cleaned/reassembled. Has worked flawlessly ever since (without being replaced).
My buddy ('97 Performer) has the fire sometimes shoot out of the venturi, outside of the bowl. We think the pressure regulator is failing, and not flowing the gas out at a high enough pressure, allowing the fire to start at the venturi instead of inside the bowl. If we tap the regulator with a screwdriver, the flame will flare up momentarily.
A new one is about $45, so he hasn't bought one yet, so I can't say for sure that is the problem. But it seems to be the likely culprit. They are known to fail on gas grills.
If yours is newer, check CS to see if under warranty.