If you see an oil stain on the front cover below the PS pump in the Vee of the block I think it is from a leaking front timming cover gasket. I have this problem also and have had the pump out and mine isn't leaking. I even put some dye in the PS fluid and looked at the area with a black light. Mine leak is engine oil, its probably one of the areas on the block/timming cover interface that is supposed to have a bead of RTV added at one of several areas. Mine leak is small also but does accumulate along the oil pan and you might smell it through the vent inside the car.
