Thanks for your prompt reply. I have re-run the program and, yes, I am sure that the menu is not somewhere else. But I noticed some more things. To judge from the way Code::Blocks itself looks, the name of the program should be on the top line just to the right of the close, minimize, and maximize buttons. It is not there. The menu should be on a black bar extending all across the window and just below the top bar. The bar itself is not there. I have clicked all around that area thinking that maybe the font was the same color as the bar, but no luck. There is a panel across the bottom of the window, as usual, but there is no menu there.
The version that I have (on another computer) that works is CB 8.02 on Ubuntu 10.04. I agree that the devil is probably lurking in the new Ubuntu Unity. I don't like it at all, but I fear I have to learn to live with it if I am to remain an Ubuntu user.
I would be very interested to know if other users of Code::Blocks on current Ubuntu releases are having the same problem.