hi GossipGirl,
My son is 8 and does exactly the same thing. We - my husband and I (no I'm not a single parent either!!) have been down the same route - specialists, psychologists, etc. There's nothing wrong with him physically or mentally - he just 'forgets' to go to the toilet. We've found the only thing that work's is getting him to go to the loo in the morning and the evening. I know just how frustrating this all is for you - hang in there, a little persistance and it will all turn out right in the end.
treborrobert - I'm sorry the mother of your child left you and your son. I'm sorry that's left you so bitter and twisted and I'm sorry you don't have a basic grasp of the English language. FYI, GossipGirl asked for help, not condemnation. Remember, when you point the finger, three are pointing back at you.