Devourer, the reason I didn't do it like that is map lag. Constantly giving units creates lag which is why I detect kill score to initiate the check. Also, you cannot create zerg eggs with triggers.

What map are you talking about, Falkoner?

Does it always work, or is it on and off?

very simple conzept...
i think you also dont need to use switches... just make this:
4Triggers
Condition: always
Action: Preverse
Action: Move Location FOCUS on Drone by P2

Condition: P2 Bring at least/exactly 1 EGG to FOCUS
Action: Preverse
Action: Give DRONE to P1

Condition: P2 brings exactly 0 EGG to FOCUS
Action: Preverse
Action: Create 2 Zerglings at FOCUS
Action: Kill 1 Drone at FOCUS
Alternative Action: Create 1 EGG on FOCUS [Use this, if u want to spawn always 2 lings when the egg dies... the egg will always respawn]

Condition: p2 commands exactly 0 Drone
Action: Preverse
Action: Give all drones from P1 to P2

HtH

This map is good for newbs to learn - it explains the basic concept.
For more advanced death detection: http://www.staredit.net/?file=510&load=edit