Yes it is a problem with the oil. Read the article red58 posted. Solid lifter cams need zinc additives for the proper break in. There developed a problem with the additive (ZDDP) ruining catalytic converters, resulting in warranty claims. So the solution was for auto manufacturers to convince the oil companies that the additives are no longer needed since today's cars use roller cams. Screw you hobbyists who use flat tappet cams.
Oils formulated for diesel use, like Rotella, still contain some zinc for now. GM and some cam companies also sell a break-in additive. Also, there was an additive called Street Legal Oil Booster by CD-2 that is high in ZDDP. It has apparently been pulled off the market but it was being found in Big Lots stores.
