As per http://kb2.adobe.com/cps/507/cpsid_50720.html I've created a single installation, effectively taking an y 9.x release to 9.3 (current).
However, Acrobat.exe gets downgraded to v18.104.22.168 (even if I start at v9.2 - yet all the other files get upgraded). When I access the menu About Acrobat Pro... the splash reveals the version to be 9.3. Something in the chain sequence or an undocumented fix :-) ?
Here's my sequence updating the ENU version:
msiexec /p "AcroProStdUpd910_T1T2_incr.msp;AcrobatUpd911_all_incr.msp;AcrobatUpd 912_all_incr.msp;AcrobatUpd913_all_incr.msp;AcrobatUpd920_all_incr.msp ;AcrobatUpd930_all_incr.msp" REINSTALLMODE=omus REINSTALL=ALL /qb
Need I be concerned?