I am really at a loss as to how to handle my situation and would appreciate any feedback.

My first fast dog, an Aussie, Jillian who will be 9 years old in 2007 who recently completed her MACH has always had contact problems. I have met with most of the best trainers in the US and gotten advise. Nothing ever worked. Now my problem is I have her son, who is 3 years old and I see history repeating itself. I just can't do this again. He is an incredible dog and this little issue is killing us.