File Overwrite Failure while uploaded

Hi around,
with the last updated version a problem appeared: files with names already in remote directory are not uploaded (only Date Modified changes). Example - when I upload my modified index.html, size 20 kb, FTP writes: 12 kb uploaded, and nothing changes in remote directory index.file except Date Modified, it shows the time of attempted upload now.
With new files everything works as should be. The dumb solution is to delete the index.html file from remote server and upload my index.file at the next instant - then it works. But obviously that can not be done for long.
In some older version there was a popup window asking To overwrite or not to - unqualified quess is that FTP prog has either switched to No overwrite version, or tries to determine and upload only changed part of my file (and fails finding that part).
Too bad I cannnot find any switch or checkbox to change that.
Regards,
Gatis

Please post the system information from the menu: Help->About "System Information"

And the log from the remote browser.

If everything would be correct a file exist dialog would be displayed if the file with the same name exists on the server.