[away3d] SkinExtrude clipping/culling

[savagelook]

Anybody know why whenever I drop my subdivision size below 20 with
SkinExtrude I start losing triangle off the mesh?  I've already tested
FrustumClipping and positioning the camera much further away.  It
seems to be a limitation of the SkinExtrude or something, but I don't
know the math well enough to troubleshoot it.  Ideas?