no VPN-Tunnel with captive portal

Hi,

I have enabled CP. As I have sometimes home-office I connected my  
enterprise laptop with check-point VPN-Client.

I put ALL MAC-Adresses of that Notebook, even the virtual of the  
checkpoint-client also as something like a Toredo-tunnel and the  
ethernet-MAC into the "MAC-pass-through" list - 3 lines all together.

But when I try to connect I get something like connection not possible

When I disable captive portal, the connection is established without problems

Does anybody have an idea - why and/or how I could making connect this  
WITH Captive Portal?

thanks a lot in advance

Ralf