I use Joomla 2.5.1, and my request is about file libraries/joomla/database/table.php. Now (in latest trunk joomla-platform - it is in libraries/joomla/table/table.php). But neverthless, request is the same. There is a function isCheckedOut in this file. I worked on my site and receive many such messages
"Strict Standards: Non-static method JTable::isCheckedOut() should not be called statically in /srv/www/libraries/joomla/html/html/grid.php on line 198"
As discussed here #1116 by AmyStephen, i change the code
Or, maybe, we need to change JTable::isCheckedOut, because it handles both static and non-static calls. I think, it is not good practice in PHP code.