VS2010: Project not selected to build for this solution configuration

Along with everyone we are moving towards 64-bit platforms. After adding solution platform x64 under Visual Studio 2010 Configuration Manager, everything seemed ok. When building, all builds was successful except x64 Release. Here is an output: 1>—— Skipped Build: Project: abc, Configuration: Release x64 —— 1>Project not selected to build for this solution configuration 2>—— […]