My understanding is that whirlwind itself wasn't change, the way diablo 2 is handling animations, movement and syncing itself was changed. I still haven't gotten any detailed analysis on what exactly was altered, but was plainly occurring is that players are very easily getting synced on clientside to perform actions that they aren't doing on serverside, causing all further commands to be garbled until you resync. Presumably, the same issue affects whirlwind, the 'rubber banding' movement, and FHR animations going bananas. Whirlwind for example is bugged in that you can start a whirlwind on clientside that isn't actually performed on serverside, thus the further commands like movement will go through, but the whirlwind didn't, so you just walk to your target.