A few days ago I noticed a small amount of oil on the ground, after looking under the car, I noticed that it looked to be coming from the bottom of the oil filter where it seal against the engine. I cleaned the area and re-tightened the filter, that was yesterday. Today I looked again and there was a fresh, small amount still accumulating on the lowest part of the filter and it seemed to come from the same place, though not enough to leak to the ground.

What could be causing this? Bad filter? All was fine until a few days ago, the car currently has 3000 miles/9 months since I did an oil change and changed the filter, I would've thought that if the filter didn't seal correctly it would've leaked soon after the oil change.

 

Carwatcher, I would tell you to do an oil change and put a new filter on it. You could have an issue where the rubber has lost contact at the joint between the gasket and the filter, you could have a bad rubber ring, etc, etc. Doing an oil change will get rid of the suspect oil filter. After that, there have been a few members that have had the seal between the filter mount and the block of the motor go bad, resulting in a leak similar to what you are experiencing. That is a simple fix as I recall since it is nothing more than 2 bolts to get the piece off and then you can get a new gasket for fairly cheap.