if you don't
uninstall the old version,
you may have still the old "ScreenshotCaptor.ini"
where maybe this "ctrl+alt+s" -shortcuts still remains ?
So open the settings dialog
and reset all the shortcuts from the right side of the picture.
Or just rename (or delete) this old INI, Screenshot Captor will create a new one at the first start.
But than you have to set your hole settings (if there any) from the old version again.
Thanks Kevin for remind me about this