error in wordpress MU 3.0.1

When I activated the plugin, I have a Fatal Error:

Warning: mysql_result() [function.mysql-result]: Unable to jump to row 0 on MySQL result index 506 in /home/educa/public_html/wp-content/plugins/event-calendar-scheduler/codebase/dhtmlxSchedulerConfigurator.php on line 34

Fatal error: Call to a member function children() on a non-object in /home/educa/public_html/wp-content/plugins/event-calendar-scheduler/codebase/dhtmlxSchedulerConfigurator.php on line 85

any idea?.

Which version of php you are using?

Latest version works correctly with wordpress mu locally, so problem can be caused by some specific version|configuration of php or mysql in your case.

php version is 5.2.14

mysql version is 5.0.91