I think stopping the training was a BAD idea. It's about bonding time and mental stimulation for you dog. The reason he does so well is because it's when you really have him mentally and physically challenged/engaged. That's what he wants and needs and can make you HAPPY AND PROUD of him rather than (I'm guessing) angry and frustrated (at home).
Can you REALLY tire him out off leash. Swimming? Chuckit? Frisbee?
HERDING, any herding instructors in your area? Agility? Flyball?
MACH3 Bretta Lee Wildhaus MXG MJG MXF MFB TQX HIT CGC TC
Glory B Wildhaus AX, AXJ, XF
"Behind every great man is a woman rolling her eyes." - Jim Carrey