I succeeded to reduce the grain perfectly by upping all the advanced indirect lighting settings. But the render time went up from some 40h to about 100.

Dont want to test all the settings, does anybody know which of them are especially effective to reduce that noise (for animation, not stills)?

Try the animation topic at Cornucopia 3D?
I don't know the answer, not being an animator, but i know it's been discussed there several times.

Larger render sizes seem to help for stills. Perhaps the same is true for animations.

I render my animations to single jpeg frames then compile them in Flash. For some reason this is the only way I was able to tame the noise, flickering, and grain I was getting otherwise.

mm rendering to image seequences is a must when it comes to animation for a multitude of reasons, gives you alot more control over postwork amongst others and makes it dead drop easy to redo a specifiq frame in your animation.

I use the image sequence option in Poser and like it for the same reasons you give too.  I have VUE Easel.  Is this available in VUE Easel or only Infinite?  I can't seem to find which version of VUE allows this. tks!