Blue Line appearing on 4x5 negative scans

I'm having this recurring issue with a blue line that appears when i scan my bw negative film. It never happens when i scan a document. I have cleaned all surfaces, including the calibration area over and over extremely carefully. I have flipped the negative in all directions; it's always in the same place. Epson feels its a "hardware" issue, so i am about to bring it to an authorized repair place. Just wondering if anyone had a similar experience. Here is a scan to show it. Sorry its so dirty- i just made this scan to print it out to show the repair place!

thanks!

I would have to agree with Epson. What scanner are you using?

-Joshua

its an Epson V850 pro, about 3 years old.