[boost] boost::noncopyable and DLL usage

The thread class derives from boost::noncopyable. While this works for static library builds, there are some ugly warnings when compiling user programs that use the DLL version of the threading lib. I suspect noncopyable not having the appropriate __declspec(export) in a DLL being the culprit. I suspect any library will show this behaviour when doing a DLL build. Is this effect known? Are the warnings avoidable? Thank you, Roland