I have a leak at the bottom of my 350 magnum filter. I changed the o-ring on the filter a couple of months ago, but not the gasket. When the o-ring is shot, it leaks from the top rim. Could it be the gasket is now shot too? The large clear plastic cylinder of the filter is brand new, so I am sure there is no crack in it. Would a bad gasket cause it to leak from the bottom like that?