Actually, the release configuration has a few differences to debug. You will notice in the debug directory that there is some random files (like application.vshost.exe and so on). That is the controlled version of the program from within the IDE. In release, these files are not compiled with your application. There are probably a couple of optimizations used when compiling release mode making it fit for release.
Long story short, when releasing something, use the release configuration to build your program. This should be found next to the little green arrow to run your program if I'm not mistaken.