Documents, Pictures etc. should be fine. Some configuration files might be a problem. It might be best to try them one-by-one and/or back-up the F17 configuration files first. The Firefox configuration (~/.mozilla) should be okay though.
Depending how the back-up was made and restored, you may need to reset the ownership of the files:
su -c "chown -R your_user_name: ~your_user_name"