how to prevent a xparticles system from emitting?

[miohn]

Hi,

I have setup 2 XParticles Systems, but I want for a certain amount of time,
that only one system is emitting/rendering particles.

Deactivating the hole particle-system does not help.
Hiding it from rendering also does not help.

Is there a way to prevent one system from emitting particles
without deleting it completely?

thanks
MIke

[miohn]

only me having this problem?

Mike