Korps,

When using a wooden servo mounting plate its a good idea once you have your pilot holes drilled for your servos to harden the wood with CA before installing the screws.

You can install the servos without using pilot holes but the chance of not getting everything straight is much greater. In either case harden the wood!

To solve your problem simply take the screws out and add some CA to the screw area letting it cure before re-installing the screws in place. Tighten the screws taut don't strip out the holes, everything should be fine.