Do your item bonuses stack? You may want to double-check. [Updated]

They certainly haven't announced it very loudly, but when player Athas complained about mana regeneration numbers not adding up just right, Blizzard poster Eilanai responded saying it sounded like a known bug. (Who knew about it is another question entirely.) The bug? If you have two items with identical bonuses (i.e. two items that both give +6 mana per 5 seconds) they will not stack. Sounds kind of an important issue to me. Anyone else experiencing these issues?

Update: A post by Tseric seems to confirm that this bug is specific to mana per 5 bonuses. Tseric also informs us not to expect a fix in 2.0.10, but that it will be fixed in a future patch.

[Thanks, Jamie]