J.,
I understand your furustration as I'm going through it myself.
My 2 1/2 year old is still not trained but he's trying.. occassionally.
Let him do it at his own pace. He wants to but he may forget, or not understand the urge to go yet until it is too late. My 1 1/2 year old has the opposite problem. She knows 5 minutes before she has to go potty and then won't sit on the toilet long enough and ends up going on the floor or in a new diaper.
My son surprised me the other morning by taking off his pull-up and putting a clean one on all by himself! Who knew he could do that? But he hasn't done it again since.
I started expecting too much of him by demanding he do things, such as thinking everyday he'd get his own pull-up on. It doesn't work that way.
So, my suggestion is, when he poops and pees on the floor to take him to the potty and sit him down anyway. Let him wipe and flush, even if he didn't go. Eventually he will catch on. It takes a long time.
Also, if he poops in his diaper, and it's not all smooshed in there, take him and the poop and go flush it down the toilet.
My son actually took his diaper off and did it himself one day which also made me proud thinking he was going to train and still nothing.
Anyhow, routine and consistency. He won't be in diapers forever, but for now, let him call the shots, otherwise he will get frustrated and not try at all.
~J.