If you developed the library using Code::Blocks, chances are you used MinGW32 to build it. Then, you are probably using some C99 features not supported by Visual Studio (I know because I had a similar problem: I used designated initializers in a Windows project, and didn't figure that broke the build on Visual Studio, because I only cross-compiled from Linux; some time later, I tried to make sure it still built, and I noticed it threw some errors, then I looked for information and it turns out MS doesn't put too much attention in supporting newer C standards; another common feature you might be using is exact sized types, which Visual Studio 2010 still doesn't support, IIRC).
It will be easy to look into it if I get the source code.