Error connecting to sql server

I have a perplexing problem. I've developed an ASP application for our internal business use. I'm getting ready to launch, but every once in a while the application can't connect to the database. The error I get is:

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)

We (IT and I) turned off the remote connections and it still happens. I'm afraid of launching without understanding what causes this and gettign a fix. To get it working again, we restart IIS and it works fine. I used VWD 2005 Express and it's running on SQL Server 2005 Express.

Thanks for any help you may have.
Scott J.

Don't let the bit about "does not allow remote connections" send you down the wrong path - this ridiculous error message is posted regardless of the actual problem (one of Microsoft's worst error messages).

The part to concentrate on is the final part of the error message, which differs depending on the actual error - in your case error: 40 - Could not open a connection to SQL Server. Are you sure that the SQL Express instance is actually running when you get this problem (is it periodically stopping?). Check it via the services applet - restarting IIS may simply be restarting the Express instance.