Screensavers are obsolete unless you have a CRT monitor which can burn in a static image.
Turn off the screensaver and use Windows 7 backgrounds slideshow by rightclicking Desktop>Personalize>Desktop Background.
You can download 120 spectacular national editions Windows 7 backgrounds, using slideshow to have a new one every time you start your computer:
120 Original Windows 7 High Resolution Scenery Regional Wallpapers Free Download » My Digital Life
Once you've eliminated screensaver interference, make sure Hibernate is enabled and set as desired in Control Panel>Power Options>Change Plan settings>Advanced>Sleep>Hibernate.