Benelli switched vendors for their slug barrels too??? I'll bet that they are trying to use the same vendor that Stoeger is trying to use. To make a very, very long story short, I used to have a Stoeger M2000. Their vendor was so unreliable, Stoeger bought the gun back. I still don't know if Stoeger is selling any slug barrels for the M2000.
I bought an SBEII with a slug barrel in the spring of '06 and didn't have any problems with cycling shells. Did your gun smith say when Benelli switched vendors?