I've just updated myNikon mount, Sigma 120-300 Sport lens's firmware to 1.02, for the new TC-2001 teleconverter I've bought. After updating the firmware, my old APO 1.4 teleconverter still works fine with it, even though Sigma states that after firmware upgrade the old tele's will no longer work with said lens.Anyone else using the same lens/tele combination? Care to share your findings. I was looking to also purchase the TC-1401 teleconverter, but it looks as though I can still use the old one and save some money.