Keep in mind, that version of copied files have to match with version of libraries on developer's machine.
If you try to connect to the same device from machines with different versions of visual studio (eg 2005 and 2008), you probably will get "device not available" error on one of them. in that case, you can copy all the files at drive:\Program Files\Common Files\Microsoft Shared\CoreCon\1.0\ from one machine to another.