IIS and VPN on same WAN connection?

We currently have a cable broadband connection that runs through a Cisco VPN/Firewall (Cisco Pix 501 Info: http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/ps2031/) and then to a switch that handles the rest of the network.  I would like to set up IIS on a Win 2K server that we can use to host a web application.  We have 5 static IP's and are only using one of them at present with the VPN.  

I'm trying to avoid putting the server behind the VPN/Firewall, so I'd like to install a hub or switch between the modem and VPN in order to leave the exisiting network unchanged.  Hopefully. this will give me a port to expose the server on as well. I think my concept is sound, but I'm having some trouble with the implementation...

I have an old hub that I'm testing with.  When I insert it between the Modem and VPN, I lose connectivity for the existing network.  It's an Asante FH 208 (Docs: http://www.asante.com/downloads/legacy/fh200bugra.pdf).  I know that most of the ports on this hub work, and I've tried them all to no avail.  I may be messing up with the uplink connection and location of a crossover cable.  Can anyone give me some guidance on what I need to do here?  I plan to buy a switch and use that instead of the hub, but I need to know that what I'm doing will work first.