I have developed an build tool the uses a script language to build several projects and generate a installation package. The problem is that some of the project are failing to build do to a "File cannot be closed because outstanding references exist." I know it is referring to a open object, but I checked and there are no objects. I assume when the project is open and built that the class libraries are been cache somehow. If this correct, how do clear the cache?

If anyone have any other suggestion, please reply.