Kenneth,
This is neither a VFP "bug" nor "feature". The fact that VFP doesn't catach it is caused by the fact that VFP can't catch it. The copy command is a function of the operating system (Windows). Even Windows doesn't know if a particular file is in use by someone else prior to attempting the copy. That's why an error occurs on the system level, not the VFP level.
George
Ubi caritas et amor, deus ibi est