DLL administration

I build some dlls to be used in a big application, and have a team working in the dlls heart of the application and another team working in the GUI, but I am having a problems in the deployment of the dll's when a change is done, because the GUI team needs or copy the new dll to the project folder, or delete the old reference and add the new 开发者_StackOverflow中文版one. Is there a best practice to deal with this problem?

I am using Visual Studio 2008 and developing in VB and C#

Thanks !!!

Put everything in source control (binaries if you must) and have people rebase when they need the new functionality.