I've also lost units like this and I'm playing the Orcs. The last one I've lost was a level 9 ogre and two level 5 berserkers which disappeared immediately after I left a large NPC city.
I've also had my units temporarily duplicate whenever I form an army and then garrison them inside my town. It's even duplicated my hero twice so far, but whenever I log off and log back on it removes any duplicates. However I can still use them once they have been duplicated until I decide to log off.
Edit: Just lost 4 more ogres and two Wolfbeast Riders to this bug. Really starting to get annoying.
Last edited by Wolvman : 12-29-2011 at 05:01 PM.