Version:            (using KDE 4.1.2)
OS:                Linux
Installed from:    Fedora RPMs

When a file is single-clicked in the Save Dialog, the dialog automatically tries do overwrite that file, instead of just copying it's name to the file name edit box as it was done in KDE 3.5.x. This happens even if the "double click to open files and folders" is selected in System Configuration -> Mouse & Keyboard.
This behaviour prevents the user to click an existing file to use it's name with few modifications to save the new file (for example, to add a sequence number to an existing file name). Every time a file is to be saved, it's name has to be typed, even if there's already a file with a similar name that could be used as a base for the new file's name.
This problem also occurs in the Open Dialog, but it's not so harmful in this dialog, once you will not want to modify a file name to a non-existing one in this case.