This was frustrating me for a bit until I found the answer, so I thought I'd put it online to help save others the same headache.
I've got a project I'm working on here at work that one other developer is working on with me. For some reason, on my machine, I was unable to change the build version from Release to Debug. The other developer had no such problem. I tried everything I could think of - downloading the source from VSS again, even wiping out the entire directory on disk to be sure I didn't have some bizarre setting. No clue what was wrong. I did not have this problem in any other project, just this one. When I pulled down the Build menu in VS2005, the Configuration Manager was greyed out. When I modified the Build toolbar to include the Solution Configurations and Solution Platforms dropdowns, those were greyed out as well. Very annoying!
Turns out that there is an option in the Visual Studio options that was getting me. I have no idea why this was only a problem on a single solution and not with any other solution and not on anyone else’s machine, but this did solve my problem. I didn’t realize that building Release vs. Debug was an advanced build configuration, but checking this “Show advanced build configurations” enabled me to chose between Release and Debug builds.
