AC3D with Second LIfe Problem

[Windhill]

Hello all
I'm really new for AC3D and registered today
to create Scarpted prim for Second Life.
but I have problem.

1) Windows XP
2) installed plug in for windws
3) Create object by AC3D and export as SL sculpted prim
4) uploded

however it is not same shape as I created by AC3D
The object always has a kind of "SPIKE".
then
I just simply make single sphere and export it but same
please look at jpg.

Please let me have solution thank you.