The shutter on my Fm2n is sticking around 1/15th of a second and slower. It was intermittent and so I ignored it, but it's sticking every time I press the shutter at those speeds. I was shooting today and it was cold out (0 degrees) and it seemed worse than usual, but it's been happening in temperatures above freezing as well. Do you think the culprit is the cold or something else? I previously used an FE2 during winter and had no issues.