When I drag a file from a remote server whose files are listed in Cyberduck to a Finder window containing a file of the same name, Cyberduck opens up a window asking me if I want to overwrite the file and showing a comparison of the two files (sizes and time stamps). However, the time stamp shown for the local file is always the current time (i.e. the time from the system clock at the moment the comparison was initiated). It turns out that Cyberduck changes the time stamp of the local file at that very moment. (If I check the time stamp in a terminal using ls -l while the Cyberduck comparison/overwrite dialog window is up, it is the same as in the time stamp for the local file shown by Cyberduck.)