Bump...
I bought this scanner last year from an RFF member in the States. Can't for the life of me remember exactly whom. Bought just before moving to Shanghai last year, and with all the tumult of that abortive move didn't have a chance to really test it thoroughly til now, one year later. It appears the vignetting is consistently visible in all shots, so it has to be scanner related.
That wouldn't be the reason it was offered for sale in the first place, would it? Well, let's not get too discouraged and still keep trying to make the world a better place, shall we?!
Moving on to a resolution of the problem: How now to get it fixed? Any ideas?