Is Iran arming the Sunni insurgency in Iraq?

Taking a page out of the US book? Speaking clearly about the Iran-Contra affair whereby America armed both Iraq and Iran during the Iraq-Iran war of the 1980s...and watched the two countries duke it out. Oliver North, Eliot Abrams...you know.

I wouldn't be surprised. Sure, sometimes some of their Shia "brothers and sisters" in Iraq might get caught in the crossfire on accident...but really, does Iran really care about any Iraqis? Isn't there a little bitterness left over from that war where millions died? Enough to arm the Sunni insurgency and keep Iraq in chaos?

I forgot where exactly I heard about this first, but I did hear about it somewhere.
Food for thought, anyway.