[SOLVED] screen savers missing

[varonbondumb]

when i go to 'system settings', 'desktop', 'screen savers', all the preinstalled screensavers that come by default with kubuntu are gone. the 'clock' screen saver still works (although not shown), although it will sometimes 'freeze', preventing the monitor from shutting off (set to shut down after 15 minutes). freezing only applies to screen saver, not the system itself. upon mouse movement / keyboard action, screen saver goes away and system resumes as normal

any ideas? thanks

edit: I am a newbie to linux and ubuntu