Yep, same thing happened to me. A few years after purchasing and installing the radiator, it started to leak where several of the tubes were soldered to the header, so I had it repaired. A year and a half later, it started leaking again at different tubes. The problem appeared to have been a bad tube-to-header solder job which would have required completely removing (unsoldering) the header and thoroughly cleaning the header and tubes. A new core would probably have been cheaper. It went to the recycling yard.
John