Opera sometimes crashes when trying to use native dialogs (open, save, print, etc.) under KDE
Wednesday, October 10, 2012 7:20:25 PM
We are investigating now. In the mean time you can work around this by setting opera:config#FileSelector|DialogToolkit to 2 or 4, clicking "Save" and restarting. 2 tells Opera to use Gtk for styling and file/print dialogs, while 4 tells Opera to use only its own internal toolkit for styling and file/print dialogs. Personally I would go for 4 as it is generally faster.
Note: When running with setting 2 or 4 Opera will no longer have styling that looks like other KDE applications.