Washboard
How do you sharpen? Machine or file? What machine? I run a Fabtek with 3/4 chain also. When that "look" you are talking about appears where I cut it can mean several things: I hit a rock or metal with several cutters, the bar is in need of a resquaring, or the chain is just dull. If you keep the top plate angle at 25 degrees (on the cutter) or so your bar will last longer and there will be less of a side thrust on the chain-which wears out the bar. Many people use 30 or 35 degrees, and that wears the bar and chain out quicker, and makes the chain wander sideways in the kerf. Also, make sure your rakers are uniform-that is critical.