I have a maxscript on two machines running Max 2010 SP1.

On my machine to activate face snaps I have: “snapmode.setOSnapItemActive 6 5 true”

But on my associate’s machine I have: “snapmode.setOSnapItemActive 5 5 true”

The snap index changed.  Why would this be different on two machines running the same software? Was this documented somewhere?  I just wasted 3 hours figuring this out.

Yes and no.
5:5 is Standard/Face
6:5 is Body Object/Face

Until you hit Max2012 when the Boby Object Snaps seem to have been moved to the top of the list, pushing all the others down 1 (or increasing their index #, if you prefer).

There’s a small script in the Help (just under the entry for snapmode.setOSnapItemActive - try running that on the 2 systems. Also, Max2010 had 3 Hotfixes after SP1, and the Connection Extension which does reference Body Objects - maybe that’s the cause?

Max 4.2 through 2013.
XP-64 (SP2)
NVidia 9800GTX-512 (Driver 266.58).
Core 2 Quad Q6600 2.4GHz, 8Gb Ram, DX9.0c.