If you can only go back 10 or 12 days, that means that you don't have older Restore Points to use.
You may want to check to see if the video card drivers are up to date. Also, if it happens only while browsing the web, delete all Temporary Internet Files and cookies and disable all toolbars and add-ins.
OneCare only backs up data per the plan configured for your profile. If you accepted the defaults, all data types are being backed up, but files within \Windows or \Program Files will *not* be backed up, even if they are data.
-steve