Jumping in headfirst with these questions now, my customer's '84 Cutlass Supreme has a driver window that won't stay up. it rolls up and down just fine, manual windows, but unrolls itself and slams down so hard it could potentially break the glass. Do we need a new regulator or is did something possibly come loose? Looking at it, with the door panel off, nothing appears to be broken, but I havn't pulled the regulator out yet.