(what else could it be in the bugs and ideas forum :P)
Played a 6 FFA against challenging AI last night on Shredded (the snow map with the 6 legged spider design). I did it to test RAM usage (which was less than 2.5GB the whole time). The bug is that when destroying the AIs bases they all had a large force of Dreadnoughts, and often other units too, in the back corner in one of the lower bits of land where the initial eco expansions are. They didn't even come out when attacking the Nexus.
That is the bug. The idea (not related and more of a request) is could you separate the unit health bars from the range circles? Or even separate the health bars from the Army number. I like the idea of being able to see the army group number at a glance but don't want the range circles there all the time, or even the health bars too to be honest.