Hi, Frank: If you have the Owners Manual, page 103 may offer some help. It looks like you have the settings right, but at the top of page 103 you'll see one of the gray "note" boxes. It states that if "[selected (pre-AF Focused]" or [Selected (Focused)] is set in AF5, the AF point will not be displayed even when focus is achieved with AI Servo AF. Try setting a different focus mode if this is the one you're using and see if the focus points illuminate then. Based on your post it looks like you have the other settings correct, so this is my only thought.
I just drug out my old 30D to compare (I never had a 5DI or II). There does seem to be a difference in that with the 30D only the little viewfinder box indicating the focus point achieving focus illuminates. On my 5DIII, also using rear-button autofocus, the light for the entire viewfinder window flashes for about 1/10 second, rather than the individual focus point(s) achieving focus. After that you're right, just the black outlines of the AF points (and the VF grid if you enabled that) are visible. I never really thought about this before. If you constantly work in low light it might be nice to have only the AF point(s) used stay illuminated, and for an extended time.