SSRS Report remote connection timeout on IIS7

I have a set of SSRS05 reports being called through the 2005 web service from our site that runs on Win2k8 and IIS7. The reports are stored remotely on another server from the web server.

In our QA environment, if we have a report that runs for longer than 2 minutes, I get the following error:

Message : The underlying connection was closed: A connection that was expected to be kept alive was closed by the server. Status : KeepAliveFailure

The problem is that the SQL server shows that the stored procedure is executed correctly, the report server shows that the report was rendered correctly (after ~15 minutes), but the web server receives that error consistently after 2 minutes (120 seconds).

This same report runs with no problems on our o开发者_JAVA百科ld environment with ran IIS6. The issue I'm running into is that it looks like long running reports seem to run fine in our production environment. The QA environment as a replicate of our production environment, just with less juice.

Any ideas? I've checked the Keep-Alive status and made sure it's enabled. I've tried changing the connection settings timeout from 120 (default) to 300 seconds and it still fails at 120. I feel that we've been able to isolate to IIS7, but I'm at a lost where to look to change the timeout setting.

Any chance you're running in SharePoint Integrated Mode? If so, see "An ASP.NET Timeout Error Occurs After Two Minutes of Report Processing" in Troubleshooting Configuration Errors.