According to that site, if the two first slots are empty, that's ok:
C-F : empty, reserved for M7091 (KE44-A)
A-F : empty, reserved for M7092 (KE44-A). slots 11 and 12 could also be empty. Some slots have only a Grant Continuity card.
Now what? Do I really want to get into this? Well maybe. The manual seems straightforward enough....ug