I have a DK45 with 200 hours on it. I have an occasional problem with the PTO and wonder if any of you might have some ideas. Sometimes the problem occurs when I'm mowing with my 5' bush hog. If I get a patch of thick growth and want to gear down to a lower gear, sometimes the PTO does not come back up to speed after re-accelerating. The PTO just kind of slowly spins -- sometimes it even slows down if I increase engine RPM. Turning the PTO switch on and off doesn't correct the problem. I have to shut down the tractor, wait about ten seconds, restart and re-engage the PTO and it starts working again. I've seen the same problem with my spray unit when I slow down or stop in the field and then start going again. I have had the tractor in for service and the dealer has no idea what the problem might be. They replaced the PTO clutch a few months ago, but the problem persists. I don't think it's the mercury switch (for the auto-PTO) because shutting down and restarting, without changing my hitch height or draft, corrects the problem. Any thoughts?