Really Puzzled ??????

I have an oil leak that I can't figure out, its on the passengar side of the car. I have changed the oil pressure switch, resealed the vacuum pump with new gaskets for the shaft and front cover, and have checked the valve cover and upper timing cover, and everthing looks good. it appears to start at the height level of the vacuum pump and of course filters down to everything else. Any assistance as to what I may be missing would really be helpful! I have chased all the common oil leaks in this car, and for the life of me, I cant find this one