Seeing as the front diff is identical, I just think it's a numbers thing.

There have not been all that many blown diffs and there are more autos and manuals.

Now member on another forum rasied a good question. Has all the blown diffs been 05 models? So far I have not found an 06 or 07 that has blown a diff. Maybe Nissan fixed something?

I think it's jsut more likely that the 05 crowd has been beating on their trucks a bit harder...though, my diff went out about 20K miles / 1 year ago.