I have the same problem with my 3 yr old gelding! We got him as a yearling and he was going to be my new cow pony. He is Half Arabian/Quarter and his whole top side is all cow lines. I was thinking with the hot blood of an Arabian and having all cow on the top side he was going to be what I wanted. He is so lazy and so slow that its not even funny! lol :) Its an act of congress to get him into a trot let a lone a lope. He knows how, and I understand he still needs to get his balance with a rider and so on. He has no fear of anything and I have done tons of ground work and driving with him. We went on his first trail ride last month with 4 other horses (all in there twenties, one being 29) and he was way in the back, I either had to get him to trot to keep up or they had to wait up! He is completly healthy, not lame, in perfect weight and current on all worming, and farrier work. He has had about 30 rides, and knows all the basics. Now I have started many colts and have had some lazy ones, but they will still move when you get after them. This guy no way, same speed.....SLOW and in no hurry to do anything! I'm about to just hand him over to my young kids, because at this point he is a fantastic kids horse prospect, lol!