Hiya.
First guess, the 'bottom' of your pillars either don't have propper triangles, or they don't have any triangles. I'm pretty sure that A6 will give you an error if you have an 'open' object, but not positive.
Next, the pillar is a seperate model than the 'floor', and when they intersect, A6 is screwing up the shadow info somehow.
I'm just guessing, so take it for what it's worth.
