dark streaks on negs

[cdat]

I developed 2 rolls of Tmax 120/iso 100 today. Had a dark streak running vertically on about 1/3 of the negs, right hand side, 1/4 in on some, 1/3 in on others. Shot on a mamiya rb67, 150 mm lens. They almost look like a light leak, except they aren't on every neg. Could they be from mishandling the film? I develop exactly, (or as close as I can) every time, have not seen these before, it is not the pattern I have seen when my son-in-law let his film touch on the roll. I will scan the negs and post them tomorrow when they finish drying.
thanks

 

[Christopher Walrath]

Wirelessly posted (BlackBerry9000/4.6.0.167 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

Maybe the dark slide was not fully inserted?

 

[MikeSeb]

I second a dark-slide problem. Could be a problem with the dark-slide lip seals.

 

[cdat]

Bingo, thanks. I switched backs, no more streaks. Now all I need to do is figure out how to repair the 120mm back.