20 years is all you get. It doesn't seem fair because they have been under a cloud, with the reexam process, but as Milestone has said, they have been valid while under investigation. There is no extention of time. Tpl seems to have been hesitate to go the full course of liigation while they were being challenged, but that still does not alter the fact that 20 years is all you get. 1995-2015 for the 336.