J.R.
I would personally try to take away the nap and put him down no later than 8 pm, he is not getting nearly enough sleep even with the nap and poor sleep can lead to lots of things going wrong in school - many kids that are diagnosed with ADD really just have bad sleep habits.
My kids usually wake earlier, and more often, the later they go to bed - the earlier they go, the longer they sleep - it has something to do with getting a second wind and the way the body works with its internal clock.
Look into the book, "Healthy Sleep Habits, Happy Child." by Dr. Marc Weissbluth - a large aprt of it has to do with babies, but then it goes on in the second half to deal with bigger kid all the way up to teens!
Good Luck!
jessie