Update for SA-MP 0.3x RC1
Update for SA-MP 0.3z RC2
Add badret(false) for OnPlayerTakeDamage

Wiki says that the return value of OnPlayerTakeDamage actually matters:

1 - Allows this callback to be called in other scripts.
0 - Callback will not be called in other scripts.

http://wiki.sa-mp.com/wiki/OnPlayerTakeDamage