i just got a rb 67 and during one of my first test rolls, the first three shots were terribly overexposed while the rest were foggy and overexposed at the edges. the thing is, my exposure reading was taken with a handheld lightmeter and was supposed to be accurate. I suspect a light leak, but shinning it through my enlarger i could see no light leaks, though the foam is indeed "gummy" and flaking off. should i get it repaired? or is it something to do with the loading of film ? i find 120 film terribly hard to load!