I've had the passenger side fail twice (replacement pipe did the same thing) - took them off and had them welded properly and no trouble since. I also had the driver side done once. They are more prone to break after adding a muffler as many shops do not support them right and it puts a lot of stress on that part (the factory weld is shoddy though).

Supercharger at 20psi would not have any effect on this unless motor mounts are bad and the motor is twisting substantially under hard acceleration.