If there is excess movement between the lowers/uppers, it is a bushing issue period.
Keep in mind the amount of movement is relative. Fox for example actually mentions the amount of 'slop' in there forks to let customers know that they are supposed to have movement (atleast when not moving). When riding a fork, some of the lubrication oil is forced up between the bushings and stanchions, 'floating' the stancihon on a liquid bearing, preventing bushing/stanchion contact and wear (at least according to Fox)
Now to add to this, the black uses a very small amount of lubrication for the bushings (it is NOT an open bath system). Manitou also does not use a true oil seal on their forks, instead they just use a dust wiper to keep dirt out. What this means is that over time, (not a lot of time in fact) the small amount of oil can and will weep past the wipers (can be inperceptable) and leave the bushings un-lubricated.
At first, with no oil, the bushings/stanchions will seem to have more slop, and can make clunking noise when rocked (could be more noticable with a loose bushing to begin with form the factory). If allowed to continue in this way, the bushings will wear fast, making the situation worse. Eventually, the bushings will start to wear the stanchions, ruining the fork.