Animation stopping

[JJ1950]

I'm using forest pro 3.9.5
Trying to get the grass to grow on a surface from left to right . . . works in the viewport, sometimes.  Seems very buggy.  No matter what I do, it won't render.  The animation stops at whatever frame I begin rendering from.
Anything I can do to get this rendered?  I'm not using a lot of grass, and its even the custom object 'grass sample' from the itoo tutorial on blowing grass.  The grass sample is animated with and FFD.  And like I said, it seems to work in the viewport, but it will also randomly stop working there as well.
Any help is appreciated.

UPDATE:  When I manually hit 'update' every frame and render a single frame, it works.  Seems there's a problem with the update on rendering a frame range? 

[iToo]

Have you adjusted the animation parameters in Forest ? (in the Animation rollout)

The default value is "Disabled", what would fit with the behaviour that you describe, because the mesh samples are updated only at certain events (for example, starting a new render).

I just done a basic animation test here, and everything seems correct, both at viewport and render. In this case i used Animation->Random Samples. I attach the scene if you want to take a look to it.

[JJ1950]

Yes, I wouldn't be able to animate at all if it was disabled.  Like I mentioned, it works in the viewport . . . sometimes.  It seems to get to a point where it decides to stop updating.  And this happens upon trying to render every time, and in the viewport occasionally.
I'm using the 'map' mode in the animation rollout (using a gradient ramp map, from black to white), though I've tried all the other options and the result is the same.
I'll attempt it in a test scene and see if I get the same result.  Perhaps the scene is corrupt?  Or the forest object is corrupt?  I'm fairly certain at this point its not a matter of user error.

[iToo]

Besides checking the test scene, please try to isolate the problem in the production scene (removing non-essential objects), and send it to us. We will check it.

[JJ1950]

Ok, here's the stripped-down scene.  It seems that switching to a point-cloud display helped with the problem--its happening less often.  However, I can't seem to keep the grass from popping on in places, even when it updates.  Again, the updates seems sporadic--if I go frame by frame and update manually, its smoother. 
I appreciate you taking a look--please let me know if I'm doing something wrong.

[iToo]

Thanks for the scene. We have identified the problem and i'm working on a fix.

What Max version do you use ? I will send you a custom patch as soon it is ready.

[JJ1950]

That's great! Thanks so much.
I'm using Max 2012 at the moment.

I appreciate it--was just about to try a far more labor intensive method, so this is right on time.

[iToo]

Ok. Please check your inbox, i just sent you the patch by e-mail.

Please, confirm if it solves the problem.