The Porsche guys are experiencing the same thing even in the GT3's. Some have gone to a BMW ABS system that cures the problem. The only problem with that is.... it's 10K
Driving style or braking style seems to be the issue according to a response I received. It doesn't have to do with pads, brake fade etc. If someone would pm me their email address I will forward the response to this issue and perhaps it can be posted here.
To be continued...