I had him tested for ADD but they said he's "just a boy" and that his "file cabinet in his mind is all mixed up."
I notice that when he is asked to draw something he has no problem. I personally think he's a good artist for a five-year-old. His dad and I have tried a bunch of things to help him understand. Do you have any suggestions?
Since your son has strengths in the visual areas, try to focus on that. Talk with his teacher and school counselor and ask them to put directions and rules in a visual form. The rule about staying in one's seat could have a picture of a child sitting in a chair beside it; the rule about listening could have a picture of a large ear, and so forth. Your son could help draw the pictures to go with the rules and directions.
The teacher could use a visual system of enforcing the rules as well; she could use a chart with a card pocket for each child. Each child starts the day with no card in his or her pocket; the first time a rule is broken the student gets a green card (warning), the second time a yellow one (time out), and the third time a red one (phone call to parent). For children who are visual, the chart can help them know how their behavior has been throughout the day. Some children who are very active may need to get a fresh start with an empty pocket after lunch. You can follow up at home with an extra bedtime story or a walk around the block just with you for a good day.
It sounds like you and your husband have tried lots of things with your son. You may want to look in your public library for a book on a positive discipline technique on which you can both agree. Then decide on rules, rewards, and consequences that you can enforce consistently over a long period of time. You may find that this consistency will help your son know what to expect and will make a difference for him.