Not sure what to tell you. I've never read that they are different and I have compared a 12 and a 10 and they are the same. Not saying you are lying but maybe the shaft is from a 13.
From another forum:
The early JK's had a style of axle shaft and then some time down the road (2011?, someone check me there) they upgraded the shafts. This thread is to serve as a repository for the part numbers and what goes with what so that people, such as myself, don't go attempting to put the wrong u-joints in the shafts or anything wild like that.
So d30... (186mm axle)
68004080AA- driver's side shaft (per the 2010 parts fiche)
68004081AA- passenger
Qtec shows that there is an updated version (presumably the axle shaft revision)
68145055AA- driver's side (current as of 12/13)
68145054AA- passenger
D44 (aka "Heavy Duty", 226mm axle)
68017180AB- driver's (per 2010 parts fiche)
68017183AB- passenger
68245209AA- driver's (current as of 12/13)
68145208AA-passenger
All of this is important....but why?
I was under the impression that we all used the same u-joint which apparently we don't (again, looking for corrections here).
2010 D30 u-joint part number is V8017757AA, which is replaceable with the Spicer 5-760x or equivalent (371 or 377 depending on your auto parts store)
I can't find the pn for the new u-joints, the old d44 u-joints were 5-7166x.