Connecting To An External SQL 2000 Server From A Vista Machine With SQL 2005 Installed

hi there - I'm praying someone here can shed some light on this - after many google and web searches, I have found users with similar issues, but have yet to find a solution.

Problem: I have recently upgraded my desktop from Windows XP to Windows Vista Ultimate (clean install) and have migrated my local machine to SQL Server 2005. However I have a number of .Net projects that access databased on another server running SQL Server 2000 - prior to my upgrade to Vista, I was running SQL Server 2000 on my desktop as well. During the install, everything seemed to go well, and I also installed the SQL Server 2005 Service pack as instructed via the MSDN site.  However, when attempting to test my .net projects on my desktop pc (ie visit http://localhost), I encounter the error:
An error has occurred while establishing a connection to the server.  When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

 note that the server I am attempting to connect TO is the old SQL 2000 server - NOT 2005.  I specify my connection info in the web.config - and it points to an external ip address on the web.

Can anyone shed some light on this?  I've tried enabling remote access on my local SQL 2005 install, but I'm fairly sure thats for servers that want to connect to my desktop, rather than my desktop attempting to connect to external servers. Any help is greatly appreciated - I'm pulling my hair out over trying to figure this out! :)

 To summarize my setup (if it helps)

Desktop PC:
Windows Vista (Ultimate)
SQL Server 2005
Visual Studio 2005
II 7.0
.Net 2.0 (ASP.Net Application)

External Server (co-located at a datacenter)
Windows Server 2003
SQL Server 2000
IIS 6.0
.Net 2.0 (ASP.Net Application)

 

 Much appreciated,

Ted