i know that in 5.4.2 unholy might was buffed from 10% str to 25% but there was a hotfix that buffed it from 25% to 35% and here the link http://eu.battle.net/wow/en/blog/11944164
in the january 6 section covers the hotfix which made the buff
there were some other dk related hotfixes which can be found there but theyr offtopic right now
plz fix this fast for us unholy dks
its easy to fix too :D