what version of Ubuntu do you use. If you use dapper and have a window open on the folder you are moving that's a known behaviour, it closes the window because it would be wrong to keep displaying something which has been moved
-- Nautilus terminates itself when deleting a folder https://launchpad.net/bugs/65001 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
