Ken,

Don' t know if this helps you now after all this time, but maybe it will help others with the same issue.

a) On the slot where the ribbon is to be inserted, is a lock clip. You pull up on that (gently).

b) Slide the ribbon in now with the clip lifted.

c) While securing the ribbon down in the slot, push the clip down, it will lock the ribbon in the slot.

Hopefully this helps, I didn't realize the clip could be lifted. While it's down, it is impossible to set the ribbon in.

ShuriKen