I think I broke the bread machine.

Well, as you may or may not know, I've recently been using a hand-me-down West Bend Automatic Dough and Breadmaker. It's been wonderful. No more bread buying and it fills the house with beautiful smells (or, scents?). I've found a few recipes that we've really enjoyed BUT recently (as in the last two loaves) the pan inside the machine is shaking violently during the kneading cycle. You know, like washing machines do when you've put waaaayy too big of a load in it. 
The loaves have turned out alright I guess, a bit on the small side but nothing seems to be horribly wrong with them. I'm just not sure what is going on, one thing is for sure. . . I really don't want to see the West Bend dilapidate so soon, I've only just begun my adventures in bread-making!