white stripes in blue channel

[Jan Nieuwenhuysen]

Lately I am getting annoying artifacts in my scans. They consist of very thin white stripes in the blue channel only along the scanning direction. They only show up in areas of strong contrast, like in this example skin and white hair against a dark background.

Is anyone familiar with this problem and it's cause(s)?

Tech info:
B&W positive transparency wet mounted (underneath one of Doug's betterscanning holders) with Kami fluid and clear mylar on an Epson V750, Silverfast Ai Studio.
I scan in RGB 16 bit.

[Jan Nieuwenhuysen]

I realise now that I have not attached the example :o
Here it is; any ideas are appreciated.

I suspect the new batch of clear mylar now. I have new scans where this happens in uniform areas, small stripes like ||||||| in horizontal rows. All blue only.