I've experienced this problem and contacted the filter manufacture. They asked if I was tightening the filter by hand, or with a wrench to the exact specs on the filter; gasket contact, then one full turn. They said that overtighting is as bad as undertighting, and that once a filter has been through a heat cycle, if it is leaking to remove the filter and install a new gasket and retighten to the proper specs. They said that most of the time retightning a filter with an old gasket that has been through heat cycles will leak worse.
Man I hate to tighten filters so tight that I break tools getting them off, but since following the procedure on the filter, life has been good on the road, but tougher in the shop with removal.