increasing the time sometimes helps, but not always--it's a crapshoot depending on the fickle forces in the tube..if you go back and look on the film very closely, you'll see the streaking--but light streaking doesn't affect anything if you're printing--I do reversals--so you SEE this stuff on a light table if it's there--therefore it's completely unacceptable.

what will give MORE reliable success than increasing the time is MORE solution--it provides more presssure to get the liquid in back quickly and more evenly---however even this can't prevent it from happening in my experience--not if the back of the film is pressed against the tube--there will always be uneven wetting back there most of the time.