Transmission jerk on 2002 Mazda Protege

I just bought my 2000 mazda protege with STANDARD TRANNY 4 months ago, after driving it 1200 miles the vehicle transmission completely blew. its got 127,000 miles on it... I finally got it back todsay after the warranty place finally accepted the claim, and holding it for 3 months. well they put in a rebuilt tranny from michigan, and it has a small jerk when i am driving steady speed, i can feel through the steering wheel, and when its in Idle the car jerks and RPMs shake. Can someone tell me what this could be? and if its serious? after putting all this money in the car ive only got to drive for 1200 miles, i cant afford to be fixing more of the problem if theres another one.

Asked by for the 2002 Mazda Protege
It sounds like the shop that did the trans replacement work did not re-connect the rest of the components correctly. TAKE IT BACK ASAP !!