CiviCRM is not E_STRICT compliant; not even E_ALL compliant. This issue is usually masked when using the UI because only E_ALL ^ E_NOTICE errors are reported. However if you run any of the cron php scripts in civicrm/bin your machine will be brought to it's knees under the weight of thousands of errors.
Ideally civicrm should be brought up to E_STRICT compliance, but at least E_ALL. Or at the very least, these scripts should be modified to only report E_ALL ^ E_NOTICE errors.