leak at oil filter 300SD

[flash123]

I replaced the lines from the oil filter to the oil cooler about a year ago. Now I have a new drip. It looks like it is coming from between the oil filter housing and the engine. The bolts feel tight. The drip started in cold weather, like single digit f. Is this a common problem? It looks like it might be a booger trying to remove and replace the oil filter housing.