Hello!
When downloading a file where the same filename already exists in the last used folder, the filename is modified to include numbers at the end... this shouldn't happen until the 'Download' button is clicked as one may well be about to browse to a different folder, where that filename may not already exist. This is the same issue you had last time you changed the download manger. Obviously, like I suspect ALL Maxthon users will say, removing the 'Open' button for downloads was a mistake.