Some Legendary items in Diablo 3, like for example Inna's Glory, are bugged. They declare to have Attack Speed, but in reality bonus is not working when equipped.
I just read the changelog of patch 1.03 and it seems they have fixed this bug, but only for new dropped items.
- Legendary items with the +Attack Speed bonus will now correctly provide a bonus to attack speed - Please note that this fix will only affect new Legendary drops. Existing Legendary items will be addressed in future patch.
In the meanwhile Blizzard develop a retroactive fix for bugged items, if I want to buy any Legendary item in Auction House, how can I understand if the item listed is new (AS working as intended) or old (AS not working)?