NLB on Windows Server 2003

Hi,
I currently have NLB enabled between 2 servers. These servers host my
company’s website. We are launching a new site on Monday and I have been
asked to allow access to this new site via an outside source for testing.
I need to assign a static IP to the new Virtual Website on the box, so I
went into TCP/IP properties and added an IP. When I click next and next, I
get an error message.� Warning-Multiple default gateways are intended to
provide redundancy to a single network (such as an intranet or the internet).
They will not function properly when the gateways are on two separate,
disjoint networks (such as one on your intranet and one on the internet). Do
you want to save this configuration? Yes or no ---It defaults to no.

IP address for NLB – 192.168.1.20
255.255.255.0
192.168.1.1

IP I am adding is 192.168.1.28
255.255.255.0
192.168.1.1

I am not leaving the network with this.

Any help would be appreciated.