Hi, sounds like you're translating Dagu's Mr General setup to Gadgeteer, I've done this one myself! Are you perhaps trying to power the servos via the 5V from the extenders? If so, don't - they draw too much power. You'd instead want to use an external supply e.g. 4xAA batteries, connect the negative terminal of the battery pack to the black wires on the two servos and also to the GND pin of one of the extenders, connect the red wires of the two servos to the positive terminal of the battery pack only, and the two signal wires of the servos to two PWM pins on your PWM extender.

If you're not trying to power the servos from the extender and already have a separate power source for them, maybe try simplifying, commenting bits out, only connecting either the IR compound eye or the servos to isolate which connection is panicking it.

RorschachUK