Has anyone else noticed that the Shimano XTR Dual Control shifters don't work well with anything except SP41 housing. I have always used high quality, stainless, slick, shift cables and high qualtiy housing on everything before. Now I notice that it is impossible to get perfect shifting without the XTR cables and housing with Dual Control. This is the same for new and used parts. If the shifting is that sensitive to what housing is being used then how sensitive is it to a little contamination in the SP41 housing?