Dark banding on scan for certain negatives

[lbenac]

Something curious happend today.
A few 120 negatives scanned on LS-8000 are showing a dark band on the side of the negative. When the negatives are turned upside down, the band goes to the other side of the negative i.e. it is on the same side in the scanner.
I have confirmed that with examination of the negative itself and scanning with the V700 instead of the LS-8000 neither showing any banding.
I have tried using the holder without glass, with my usual AN glass, multiple pass nothing change this. I have tried other negatives and they scan as usual without problem.

I am at a loss to understand what is happening. Could their be something in the base of the negative that would trigger this effect on only one side?


ANybody with similar experience?

Cheers,

Luc