I have a Rennack (sp) german made 5/8 straight that has been one of my "go to" razors. It was one of the first razors i was able to sharpen well and it always gave a good shave. now i can not seem to get the thing sharp! I have tried everything i can think of. I have even successfully honed a few other razors between my attempts to rehone this one. Has anyone ever experianced this?