Open Connection error

[DavidC]

We just moved our SQL Server 2000 database to SQL Server 2008 using the exact
same security settings but on a new server. Now we are getting the following
asp.net error when trying to access the web site remotely.

Cannot open database requested in login 'Marshall'. Login fails.
Login failed for user 'sa'.

I have the connection string the same except I changed the server name. If
I access the server via SSMS and enter the sa and password, it opens fine.
How can I find out where the open connection problem is?
p.s. I added Network Service to the SQL database and it still failed. Thanks.

 

[DavidC]

Turned out to be a router problem that was routing the incoming request to
the old server. However, I will keep your "trace" idea for any future
problems. Thanks.