[zabatron]

Jumping out of gear is usually caused by worn/faulty syncros,but the Getrag/Ford IB5 gearbox, as fitted to your car, was notorious for jumping out of 2nd gear even when new.Check that the gearbox fluid level is correct,and also check the condition of the gearbox fluid as I have seen burnt Ford factory fill gearbox fluid in many Fiesta manual gearboxes(the Fiesta XR4 I used to own had burnt gearbox fluid at 30,000km).