Evil, I know this isn't any real help w/o data, but the Lund tune is now fixed from this stuttering as far as I know (it certainly is for me). He said it was in the tune and not the plugs, at least with the 91 and 93 DD tunes. Their 93 SS tune still hasn't been updated. From the little I know, one of the factors was the colder temps increasing boost more than expected.
For me, it got worse and worse as the temps dropped, but with the new tune, and a temp of only 26F this morning, it pulls very smooth from any combination. Now what happens when Summer returns, I don't know.