In CNN but not in the Washington Post today: it would appear the "giant weapons cache" was gone before we got there:

The mystery surrounding the disappearance of 380 tons of powerful explosives from a storage depot in Iraq has taken a new twist, after a network embedded with the U.S. military during the invasion of Iraq reported that the material had already vanished by the time American troops arrived.

Oh, that's right, sorry. Must've been my seeing-eye dog typing...

Update: Jason notes that the whole stockpile issue is a complete non-starter if you've ever actually visited the country:

Every tribe in Iraq has huge weapons stores of its own, which they used to hedge against other tribes in the event of a collapse of the Hussein regime. Members of my own battalion dug up mortar shells by the hundreds, and artillery shells by the dozens, the whole time we were there. Digging up another weapons cache was almost a daily occurance at times in Ramadi.

And every few days, we'd get a notice that 30 or 40 or 50 tons of explosives were about to be detonated out in the desert south of Ramadi or west of Fallujah ...

370 tons of ordnance sounds like a lot. And it is. But if you know Iraq, it's really a drop in the bucket.