Link out regon glitch in the Lost Stonehenge age

Im working on an amature version of the Stonehenge for Drizzle and I discovered an area between the two Trilithon Stones that causes the AV to panic link. The area between the stones is not wide enough to walk threw but if you try it will cause the AV to look as if its falling and then panic link. I had the same issue with part of the ramp in the checkers age. if you ran up against the flat part it would do the same thing. at first I thought it was a strange interaction between autocad (which i made the ramp in) max and plazma. so I made the ramp in max and it seemed to resolve the issue, but I have not imported anything for the Stonehenge age from Autocad and the problem is coming back to haunt me.
any idea's?
any idea's?