floating point exception
 

hi everybody I tried to model a viscous flow by "pressure inlet" and "pressure outlet" in CFX 5. But there is a trouble and CFX announced "floating point exception" and suddenly solve is terminate with error. I can't solve my problem. I studied CFX manual. It offers that applicants should use "velocity inlet"! But my problem is that I have to use "pressure inlet". I applied inlet, outlet and opening boundary conditions together but solve failed too soon. I could solve this problem by using Fluent. Unfortunately it seems that Fluent is not able to solve "porous media" and "VOF" coincidently. What can I do? I would be very grateful for any advice.