I ran into that several years ago and wouldn't waste my money on a regrind again. I had mine reground after a lifter failed and caused what would be considered light damage. I ran that cam 1 season and when I tore it down the next winter I found grooves in the lobes that matched the rollers. I called comp and they said they probably cut through the surface hardness when they reground it. When I asked why it hadn't been hardened after it was reground they said that would make it too hard and likely to break. They also told me that my problem was rare but when I talked to a guy at a local machine shop he said every one he ever sent back for a regrind did the same thing.