Is something wrong with my circuit breaker?

Well its the original one that came with my trailer which was in 1975 my Mom put a new water heater in but its a gas powered water heater and she put a new stove that we got for free in its electric but in my room I have 2 Desktops, PS3, mini fridge, Xbox 360, TV, Timewarner DVR, desktop lamp, 1 wall light, Xbox 360 HD DVD player, stereo system, and a phone and in my Moms room theres a stereo, cable box, tv, 2 wall lamps, in the kitchen theres a electric oven, microwave, fridge, toaster oven, oven fan, ceiling lamp and a tv and in our living room we have a desktop, DVR cable box, tv, router, modem, surround sound, printer, and 2 lamps why is it tripping oh and I have a laptop and other game consoles I plug in but theyre not plugged in all of the time