Ray trace depth shouldn’t affect surfaces that aren’t set to reflect or refract, surely?
Makes sense now. With little rendering of glass filled windows I have done I have used reflect and refract and had to increase the raytrace to get the desired results. I try to avoid these types of raytracing until I get a more powerful computer with tons of ram. 
I also remembered what adam said above, a while back on the old forums and couldn’t work out why I was getting a shadow from hair that use transmaps with no reflection or refraction…now I know thanks Richard.
