Im facing some problems with this combination, I use optical cables, and when I try to use TTL, the YS110 not fire, or fire with few power. When I use the new D1 strobe, I don´t have this problem. The YS110 only works without problem in manual mode.
Regards,
Luiz Felipe
The following link will take you to the manual for the YS-110. It has instructions on page 13 and 14 for making sure your mode setting is correctly positioned.