I had the same problem with my D2 and a 135 mm. The same problem also appears when using a 80 mm and the condensor in the upper slot. So, now i print without a condensor when using a 135 mm, and with the condensor in the middle slot when using a 80 mm. Never noticed a loss of sharpness with this construction, but i didn't do any comparative testing. Someone may correct me, but my understanding is that the condensors are meant to provide an even illumination of the negative and have no direct influence on the sharpness of the print.

Huub