Why does the sample diet in the CBL book say no carbs in the pwo shake after the 4pm and 6pm wo?  10:00am I get, but I don't understand not having it after 4 and 6 pm.

I wouldn't use the meal plans in the back of the book. A bit of searching around the forums you would have found out how to do the PWO Shake. Whenever you train in the evenings, you can have some carbs, like dextrose in the PWO Shake. Some people don't because not all the time will it agree with their system. So they just have a PWO Shake sans carbs and about 30-45 minutes later they eat a low fat carb protein meal and roughly an hour later can have junkies carbs as the last meal. Or depending what protocol you're doing.