Sounds like to me you may have a couple problems, I've been with a kubota dealer for 8 years as well as dealing Bobcat skid units. I do know the Kioti and Bobcat tractors are the same, bobcat just rebrands the kiosk, but we don't have the bobcat tractor line, but to the point, it sounds like to me there may be more than one issue depending on how the tractor/trams/pto type is & it's set up. If the tractor still rolls and you have to hit the brake, I would ask what does this do to your tractor engine rpm? Does it dip? After you stop the mower blades & drive stops so does the pro then disengage without grinding? When you hook it up is the tractor running? (Bad idea btw) the pto may slowly always spin with the tractor running, on some machines. But does it spin relevant to engine rpm? I ask this this of course with the pto lever disengaged. Without being in front of the machine it would seem like if your hitting the brake the momentum of the spinning blades propells you forward so your main clutch is not disengaging from the tranny. But maybe whatever is causing the error in the main clutch can be also doing the same for the PTO clutch packs to not disengage. Have you check your fluid levels? It could be simple and be something like to much pressure in the tranny from being over full, it does happen. Check your fluid levels and how long has it been since you changed your had filter(s) some have two, suction & return. Also just a reminder as this wouldn't be effecting this situation but while on the subject of fluid, remember that most all implements don't come with the gear boxes filled with fluid, it's a hazard for freighting so always check & use 80/90 gear oil or check your manual for fluid weight. You would be surprised how many problems a new filter will take care of. ~JP~