My marauder (Nida, Ajunta Pall) was doing the Primal Destroyer world boss on Belsavis last night. In the group was another guildie's alt and marauder, Venrill (complete combat log at the bottom).
In the process of killing the boss, I noticed that several of my vicious slashes appeared to be not stacking fury. Nida currently has just under 101% accuracy on her mainhand, which means she should not be getting mitigated much on bosses.
Further, I have searched the logs and in that fight, there were only 2 misses, and they were back-to-back with a hit, which means that my offhand weapon missed in the slash only twice. I've pasted those selections from the log below.
When I mentioned the misses on mumble, my fellow guildie said that some of his vicious slashes appeared to not be stacking fury either.
My understanding is that fury should be stacked when using any rage-spending ability. At one point, I filled my rage bar and dumped it to recreate the lack-of-fury-stacking, (you can see that at 23:33:11 through 23:33:17). Only about half of those strikes built fury.
Am I misunderstanding the mechanic, or is there a bug happening here?
Nida and Venrill are both Annihiliation spec'd marauders, 31/3/7 - although Venrill has 2 points in Phantom, while I have 2 in Subjugation.
COMPLETE ENCOUNTER LOG HERE: http://pastebin.com/DjyhcNts