Weird behavior: drawing aggro and intimidate symbol
So, lately (post-enhancement pass) I've been noticing some rather odd behavior when running my rogue, where enemies will occasionally show the intimidate symbol above their heads and aggro on me, sometimes simply when I approach them, without having hit them at all yet, and even with allies already beating on them. This happens sometimes on approach, and sometimes while in a group attacking something.
Now, I'm used to occasionally drawing aggro from weak DPSers even with the full threat-reduction enhancement line and a -20% threat item (maybe 2, if the Assassin set bonus and Tinker's set bonus stack), but this is happening even immediately after a successful Diplomacy or Bluff, and even with solid DPS who should have much more aggro established than me.
Is anyone else experiencing this behavior? Any idea what it could be from?