Got this link off the Xterra forums:
http://www.ncconsumer.org/Nissan%20Fron ... efect.html
Moderator: volvite
We have learned that sometime in late 2007 Nissan Motor Corporation issued a warranty extension for the transmission oil cooler / radiator assembly for the subject vehicles to 8 years, 80000 miles – up from the standard 3 year, 36000 mile bumper-to-bumper warranty. The warranty is limited to the radiator assembly only, not the transmission, and does not address related failures of the transmission from the mixing of transmission fluid and coolant. Nissan Motor Corporation, to our knowledge, has not been conducting any preventive inspections of the subject vehicles to help consumers prevent catastrophic transmission failure. Consumers report that Nissan Motor Corporation is denying warranty claims on these parts and as a 'courtesy measure' will offer to replace the failed oil cooler at a discount, but will not offer any other compensation or assistance for damages to other components.