Hi boffin
Notices are not really errors and on a production system they should be disabled in PHP anyway.
Joomla usually has it's own way to handle error/notice messages in its global configuration.
But u can check the values for "display_errors" and "error_reporting" in your php config.
Sure I agree, notices should be avoided where possible and I'll check it out once I'm able to again (I'm currently busy recovering from a serious server crash

), but they are nothing to be worried in general.
Hope this helps for the moment
Greetz
FoTo50