I have a Powermatic 1500 bandsaw, and am using 3/8" 3tpi blades since I mostly cut green wood. Occasionally the saw will start jerking forward in little bursts during a cut, leaving rough, nasty-looking ridges on the cut surfaces. It started today between one cut and the next as I was chunking up some birch (varying thicknesses from 3-8"). After the first jerky cut I stopped the saw, checked the guides (AOK), made sure there wasn't any gunk on the tires and tried again. Same result. The blade is really clean and new (a few days of gentle use), the tires are in good shape and the guides are all where they're supposed to be. The bad cuts feel like the sawblade is suddenly grabbing in a weird way, and jerking forward a little. I also checked to make absolutely sure the work piece was flat on the table and it was. Anyone else encountered this? Did you figure out what was causing it?