having a problem with skin cache

We’re having a problem with one of our characters when the skin cache is enabled. The vertices in his head chunk do not get transformed correctly – instead they all lie in one plane.

Is there a limit to chunk/vert/bone counts when skin caching is enabled? Our other characters look fine. This one in particular is our most complex in-game character so I’m wondering if we’re blowing through a buffer size somewhere. I did notice that if I reduced GMaxGPUSkinCacheElementsPerFrame to 1, the problem goes away, but I’d rather not do that.

Any help is much appreciated! We’re on QA approved 4.2.

Thanks,
Chris Ledwith