Mangos Version: r8235
Custom Patches: ACID 0.1.0
SD2 Version: 1254
Database Name and Version : UDB 0.11.5 (381)
How it SHOULD work: Ever since WOTLK, steady shot shouldn't be interfering with autoshot, which means even if you are channeling the steady shot, auto shot will still be shooting whilst it's channeling.
http://www.wowwiki.com/Hunters#cite_ref-MMO-champWWI_2-2
How it DOES work: Casting steady shot interrupts the auto shot.
Auto Shot - http://www.wowhead.com/?spell=75
Steady Shot - http://www.wowhead.com/?spell=49052
Also, if you stand for too long without moving or turning, auto shot will stop firing for no reason.