I purchased a Konica Minolta 35mm scanner and had excellent results but tremendous grief. I purchased through Amazon.
I called Minolta USA for support..they told me to send it back to them, but it would take a few weeks to fix because they'd received too many cameras as well as scanners with complaints. I think bad quality control was Minolta's curse.
When I contacted Amazon about this situation they told me to return it to them because ALL of those scanners were trouble. They asked if I wanted refund or a Nikon scanner. I said Nikon and had it two days later by an express Fedex...before I got even the Minolta repackaged ! The Nikon has been wonderful with all sorts of transparencies. The only film it hasn't been able to handle is a project I shot with Kodak's 35mm Kodalith...for that I've had to revert to my old Epson 3200, which isn't as high resolution but was OK for the purpose.