I have a 2005 23hp 52" Lazer HP. It keeps shutting off everytime the handles are pulled in. The parking brake still works however. When you let the parking brake off, the mower can't be cranked, and when you stand up off of the seat, it shuts off. When the handles are pulled in though, it shuts off with the parking brake set or when it is off. What sensor is causing this problem? Both handles individually will turn off the mower. Is it the brake sensor or both the handle sensors? Thanks.