VPN problem in vista

Hello everyone
in windows XP i was UNcheck the default gateway for the vpn connection i
create , so i can access the remote network without to have the destination
gateway as my internet gateway

when i do uncheck the same box in windows vista vpn connection, it come back
to checked by default when connected??
i installed SP1 for vista,
that means my whole computer having the remote vpn gateway as its internet
gateway.
any Help !!
is there any solution may help ??

thank you.

A.Sabry