In short, sometimes when I go to update a unit queue in a factory, I lose the buildorder of whatever I happened to be building. Examples include trying to add engis in a build order on top of the engi that is currently being built, then having the engi under construction removed from queue at 75%, building 2 strat bombers in queue from air HQ, cancel one of the strats, just go have the 95% strat bomber cancelled as well. I also sometimes have naval factories stuck trying to build air units, land factories trying to build navy, ect ect.
I can also get fairly decent UI lag, but not consistently of often, not sure if there is a relation.