OK, so this one isn't about agile. But, it's such an annoying pain point I thought I would share. And, I couldn't find much info on this error message out there in the ether.
Visual studio complains every time the solution is opened: "... discrepancy between the solution's source control information ..."
When using Team Foundation server for source control (also the same issue with VSS I presume), someone on my project decided it would be better to use the source control server's IP address in the project SccAuxPath entry, instead of the server's name. They may have been experiencing DNS issues, or something like that. I recommended to the team that if this were the case, and DNS was not dependable, to put the IP and the server name in their c:\WINDOWS\system32\drivers\etc\hosts table. This "discrepancy" confuses the poor little source control system, and it senses that there is a difference between the server's name (to which it has a TCP connection already) and the target destination specified in the project.
So, it checks out the file, expecting that it will have to change something. Then, it is able to connect using the IP, and everything's fine. Except, the files are left checked out with no changes.
Here is the fix:
simply change
<SccAuxPath>http://10.10.10.10:8080</SccAuxPath>
to
<SccAuxPath>http://TFSSERVER:8080</SccAuxPath>
and problem is solved.
Just remember that TFS is relatively easy to confuse... Now, just go ahead and retire TFS and use Subversion like the rest of us 