New Durango strange misfire

Just bought a new 06 Durango. 15 miles on odometer. It has a misfire, especially at around 10% throttle 42-47 mph. I do notice some misses at other speeds, but it is the worst around 43. I checked the sticker, and it looks like it sat on the dealer lot 8 months or so.
I suspect fuel gummed up something. I asked dealer to check it out/ fuel system cleaning. Even took the service rep for a drive to show him the problem.
When I picked it up, the paper work said no engine codes, scan was clear. Nothing about fuel system clean. Service rep said, 'Oh yeah.. we cleaned it out. Should be fine now.' No change, still misses.
If the dealer did cleaning, wouldn't it be on the paperwork so they could bill Dodge for the warranty work? I'm I getting the blow off so far or am I just paranoid?
I'm thinking of putting some injector cleaner in the fuel myself, but with a brand new truck.. I think the dealer should fix it.

Went back to the dealer. He said he was mistaken, and the tech only put fuel cleaner in the tank.. no machine was used.

Went for a drive with the service manager. He said it was the torque converter in partial lockup, and this is not a problem during the breakin period. He said should clearup by 1000 miles or so.. So I guess I'll wait a few weeks and see.

Anybody else notice this shuddering during breakin?

what size engine there is a tsb for a 4.7L 18-024-06

It's the 4.7. How do I lookup that TSB number? Did a google, came up empty.

Thanks, Mike