thanks for the speedy reply, already i feel the knowledge growing! I was just outside adjusting a knob and i broke.... i guess thats plastic tensioner for you!
I ended up exchanging the ryobi 16" for a mastercraft maximum 16" scroll saw, the blade runs in perfect line, and the whole thing feels much better, also the tensioner knob is no longer there, instead its a flip type switch that i guess sets it to specified tension.... so far so good!