I keep reading all the 'how to sharpen a chain' posts, including the specific advice to my own threads. I feel I am sharpening the cutter OK and feeling much more comfortable with the consistency of my stroke. I'm using the basic Oregon guide so that holds the file at the recommended height and gives me an angle reference. I give each tooth a couple strokes and can see it clean up whatever irregularity might be present. I'm currently using a new Oregon 91P chain. I dropped a 12" hickory and bucked it up yesterday. I started with a freshly sharpened chain. I had to sharpen it once again about half way through (actually should have done it about 1/3 of the way) bucking it up. My saw tore through it while dropping it (big chips, felt it literally pulling the saw through the cut) and the first 1/3 of the bucked logs. Then it just seemed to cut noticeably slower so I stopped and sharpened the chain. I did not notice any damage and was trying very hard to keep it out of the dirt. I don't recall hitting anything but I know I can't see a lot of what is under the log. After sharpening it was ravenous in the wood again, then slowed down after about the same amount of cutting. I had checked the raker height before heading out but the chain is relatively new and they were fine as per my .025 gauge. One could think I must have hit some dirt or a rock, but this just seems to be my cutting pattern. Everybody else seems to get far more cutting per sharpening than I do. Let me mention one other thing I've noticed. When I go to sharpen it I frequently see a small amount of hardened wood/sap(?) stuck to the top and/or sides of the cutter. My chain doesn't fling oil, probably could use more oil flow, but I at least see a thin coat on the chain whenever I check. Is it possible this wood sticking to my cutter is causing my problems? Could it be a low oil flow issue allowing the wood to stick and impact cutter performance?