You try to cancel the save of an activity form programmatically by using a custom action in the OnSave event in Microsoft Dynamics CRM 3.0. However, you cannot cancel the save because the custom action in the OnSave event does not run.
This problem is fixed in Microsoft Dynamics CRM 3.0 Update Rollup 1. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
Update Rollup 1 is available for Microsoft Dynamics CRM 3.0
For more information about the terminology that is used to describe Microsoft software updates, click the following article numbers to view the articles in the Microsoft Knowledge Base:
Description of the standard terminology that is used to describe Microsoft software updates
Microsoft Business Solutions CRM software hotfix and update package naming standards