Yes, when first booting, the mobo will go into the soft menu, to allow you to introduce it to the new CPU. However, I did not get the message "CPU is unworkable or has been changed". I did have issues in POST with the BD-7 (not the II) board I first had, it just wouldn't boot. I believe that may have been related to the later CPU (512K).
Good luck- I'll be happy to help wherever I can.
Bruce.