Hello. I have this "new" 50mm f/1.4 SSC lens that is showing very slight haze on part of one of the front elements (but I cannot make this out very clearly). I can barely see the haze if I shine a bright light in to the lens or look through it in bright sunlight, and that too if I let the shadow of the hood pass over that hazy part. Also, there appears to be some oil on the aperture diaphragm making is slightly sluggish (I can hardly make the difference in closing speed, but looks a tiny bit slow compared to a clean 50mm f/1.8 lens I have) when closing during a shot. I have seen this web page which shows how to disassemble the lens and clean the diaphragm: http://rick_oleson.tripod.com/index-161.html So, what would the experienced users say regarding the lens. So, should I try and go ahead with the cleaning or try to return it? Thanks.