SQL.NET connection error in Active Directory

[john.js]

This has been driving me crazy for past few days so I hope there is an
answer here...

We are moving from NT to AD and the web app that used to work fine
stopped working with following errors: SQL Server does not exist or
access denied.

I am using Windows authentication as it's an intranet app and recently
enabled identity impersonation to true...

Here is the kicker though. Whatever I do ( I tried impersonation
method here: http://www.15seconds.com/issue/040511.htm ), I always end
up getting that SQL connection error unless...

1. log into the server
2. open the web config
3. save without changing anything
4. log on to localhost of the site

Then it works... and I can get online from other machines as well.

Obviously I can't log onto localhost every minute as it will time
out... and it seems to be application cache problem... but.. why is it
doing this and how can I solve it?

Any solution is welcome although less change to the code would be
nice.

Help~!

John