If something is solid and works, why go playing around? I don't understand when guys will say 'I ran such and such a program for 3 months, made great gains in the gym, gained quality weight, now I stopped and am running something new'.....You'll eventually hit a wall, just modify and change some things to work around it.....like was said, make sure you are sleeping enough and don't follow the metrosexual diet.....eat, and eat, and eat, your body needs it....
For example, look at any solid program, to get off 5x5 a bit, look at WSB, the guys there change and tweak and modify, but they're successful because they run the same program and work through plateaus....they don't run 10 different programs per year.....same with Starr, his routine is tried and true because he ran it on countless athletes for years, he didn't stop after 8 weeks and do something else......just be patient and ride it out.