Created attachment 360546 [details, diff] pax-patch applying cleanly for nvidia-drivers-331.13 (with -p1 in $S) nvidia-drivers-331.13 cannot be emerged with USE=pax, because the nvdidia-drivers-pax-usercopy.patch does not apply (because of different whitespace and since some constant strings are now written as macros). I attach a modified patch file which does apply cleanly.
It's in the tree.