I have the same problem.  I also notice that nay unit that has maul, mine included, does the same thing.  They make an attack, then sit there for a minute or two, then I get the big "maul" notice and another big pause.  I now just scrap mauling weapons out of frustration and use up mana killing bears before they can melee.  Not sure why the same thing happens with Forsaken Martyr.  I can't remember that unit having a maul attack, but then again, I usually go do something while I'm waiting for the battle to process, so I might have missed it.