Comment 1 for bug 831056

I've not encountered this behavior before.
Could you advise what host is using the plugin?

All I can think of right now is:
1) The reverb space is not being initialized - is the activateIReverbER function being called? I'm pretty sure this isn't the problem as the reverb space is 2s in size, so if this was the problem you'd have 2s of noise.
2) The room dimensions are changing - I handle that by cross-fading between the old room and the new during the 'run', perhaps something is occurring here that is creeping through? eg before the first 'run'?

If you could post a bit more information about the host and the nature of the plugin use I'll try to reproduce it.
thanks,
Fraser