SonicWall 1-to-1 NAT problem

I recently assigned a new IP to our NT server and created a web in IIS with the assigned IP. I then established the One-to-One NAT so outside users can access the site. However, the site does not respond on the WAN. We can however access the site across our LAN. We can ping the
IP across our LAN, but we can’t ping the the associated One-to-One NAT IP across the WAN. Any thoughts?