Custom field update issue

Hi All,

In Project Server 2010, I am trying to update 14 task-level custom fields values (all number types), all at once, by writing a OnPublishing event handler using PSI. The solution works perfectly for plans having around 260 tasks. But for plans with more than 260 tasks, the fields are updated till 260 and for the subsequent tasks, the fields are not updated. Is there any minimum value for the number of custom fields that can be updated at once?

Thanks.