Fatal error: Maximum execution time of 60 seconds exceeded in common.inc on line 552

Hi all!
In all pages of the admin menu on openpublish i see this error: Fatal error: Maximum execution time of 60 seconds exceeded in C:\xampplite\htdocs\drupal\includes\common.inc on line 552
but in this file i have no max_execution_time to change..
How have i to do?
thanks