Polaroid 667 - strange markings

I hope someone can help me here. I am new to Polaroid. I am just shooting my second film box. I have strange yellow/white markings on prints from 667 film. There is usually 4 up to 6 vertical stainings on each print from this box. They are white with yellowish borders. Is is bad film or I do soething wrong?
thanks a lot,
Jan

Do you have a scanner? If so scan one image in so we can see what it looks like.

I've recently have had QA issues with Polaroid 66x pack film. For every 10 packs I have used, up to 3 entire packs have had QA issues and another 2-3 packs have had QA issues in one or two of the individual films. But instead of 'streaks' like you are describing, I've had 'burn' blotches.

Polaroid is pretty good getting me replacement packs, but even the replacement packs had issues and it's quite a pain.

Regards, Art.