[Doug Funnie II]

I had the same problem. Basically after two months I was no longer able to keep adding more weight even though I was getting 4 days rest between workouts. What solved the problem for me was incorporating suitcase deadlifts immediately after doing squats. I think suitcase deadlifts help because they build a lot of strength at the bottom which is where most people are weakest, and they hammer the stabilizing muscles.