I recently acquired an yamaha p115 (yesterday!) and I noticed a weird behaviour from the sustain pedal. Basically, if I press the sustain pedal a few seconds AFTER I release a key it produces a sound. It is very odd, I let go of a key, it goes silent, I press the pedal and it sounds as if I had been holding the pedal all the time. If I press and release the pedal quickly the sound goes away and back over and over, making a "woo..woo" sound. It is driving me crazy.

I have tried 3 different pedals, including the cheap yamaha pedal that came with the keyboard, and had no luck.

Any ideas?