I'm experiencing a critical bug or quirk in moving/copying files. It happens for example like this: I just want to move a directory, say 5-15GB, including a couple of movies or something. I have the source folder open and the destination folder open. So those two windows sit there and I start moving (for example by cut & paste method). The transfer progress window normally appears and everything is normal. Now, if I just close the source folder window, things go wrong. It still moves for say a minute, but then, suddenly without notice, the transfer progress window just disappears as if I pressed Cancel. I just tested this carefully and I just closed the source folder window and made a Thunderbird window active (while TB was doing nothing). After a few seconds, the transfer window just disappeared and the file transfer was cut; the file in progress vanished from destination just as if the transfer was canceled. I did not touch mouse or keyboard and nothing visible happened on my computer. I don't think this problem ever occurs if I let the source and destination window sit there until the end of the transfer. Has anyone else encountered this? I'm pretty sure this is not normal behavior, especially since source and destination are just normal internal hard drives without any disruption or disconnection.