The pulsout command just flips the state of the pin. If the pin were high it gets set low, if the pin were low it gets set high. Although you might expect your starting state to be always low, real world interference does happen and you must set the pin state low to be really sure. I spent days hunting low level random servo chatter in my UAV controller which was corrected by initialising the pins before calling pulsout..

1. Try presetting the state before calling Pulseout.
Low servo1
low servo2
pulsout servo1, forward
pulsout servo2, reverse

2. Current draw causes weirdo effects.
When you demand a large movement from one or more servos almost instantaneously the servos will draw high current. Although the servos draw small average current, they pull high instantaneous currents. About 1500 mA for a standard size analog servo and about 5000 mA for a digital servo (as measured on my JR servos). This can cause your power supply to sag and give you weird outputs. I always drive my RC logic from a separate power supply to the servos to minimise this and stagger servo operation with the maximum possible delay between each servo movement.

HTH
Brian