I ve just realised that the klipper behavour has changed. When i copy a selection ( eg a phrase) and i want to paste it and replace another phrase, i select the other phrase and after i do paste. Then i dont paste the first copied phrase but the SECOND that id like to replace !
Before it was nt like that.

i have the kde 4.4.2

Right click on the klipper system tray icon, click "configure Klipper", and near the bottom uncheck "Synchronize contents of the clipboard and the selection"

Thanks , it works as i wanted with this setting