We have an instance of SSRS 2005 that is giving us the following issues... unfortunately they are intermittent and so far I have not been able to pin down any particular reason for them.
1. After running a report, if we try to navigate to another folder (Home for example) the page just hangs. It's not all of the time, and it seems to happen more often with larger reports, but once it happens the only way out of it seems to be closing IE and reopening.
2. When running a report with a lot of pages, say 50 or more, the first page will come up normally but when you try to go to the next page, it throws an error saying that it cannot find execution <guid>. This one has only happened a couple of times.
3. Some users have reported getting error "SQL Server Reporting Services Error: The request failed with HTTP status 401: Unauthorized." when they try running a report, almost immediately. The same users have also reported that a few times they have been asked for username and password (as a popup by IE, not the one that appears when the data source is asking for it)
These issues seem to have started in the last few days. I am not aware of any changes made to the server or to the network. #3 makes me suspect that this may be a network issue or perhaps an IIS issue, but I figured I would throw a line out here, in case anyone has resolved similar issues.
I am seeing in the SSRS Web App logs some errors saying that it's unable to read data because an existing connection was forcibly closed.