As part of Microsoft's continued commitment to respond to customer asks and issues, they have released an Update rollup for CRM V3.0. Among others, this rollup also includes a number of specific fixes for some minor issues related to the programmability and SDK. This includes fixes to callouts and form events. You only need to install the update if you have experienced the specific issues described in the update description.
Key issues that are fixed in this update rollup -
Update Rollup 1 for Microsoft Dynamics CRM 3.0 contains fixes for the key issues that are described in the following Microsoft Knowledge Base articles:
910242 (http://support.microsoft.com/kb/910242/) You receive error messages when you try to send or promote an e-mail message in Microsoft CRM 3.0
911316 (http://support.microsoft.com/kb/911316/) Error message when you try to reply to an e-mail message in Microsoft Dynamics CRM: "An error has occurred"
911520 (http://support.microsoft.com/kb/911520/) E-mail activities are not automatically sent to the recipients when you distribute e-mail activities for a campaign in Microsoft Dynamics CRM
912061 (http://support.microsoft.com/kb/912061/) Some fields are not available as search criteria when you use Advanced Find in Microsoft Dynamics CRM 3.0
912208 (http://support.microsoft.com/kb/912208/) If you delete the contents of some of the address fields in a Microsoft Dynamics CRM sales order, the fields are not updated in Microsoft Dynamics GP
913468 (http://support.microsoft.com/kb/913468/) Error message when you try to start the Microsoft Dynamics CRM 3.0 client for Outlook: "An Error occurred loading Microsoft CRM functionality"
913549 (http://support.microsoft.com/kb/913549/) An update event does not trigger the callout function in Microsoft Dynamics CRM 3.0
915343 (http://support.microsoft.com/kb/915343/) Error message when you use Microsoft Dynamics CRM 3.0: "Buffer overrun detected!"
915791 (http://support.microsoft.com/kb/915791/) An appointment time may change when you synchronize Outlook with Microsoft Dynamics CRM 3.0
916630 (http://support.microsoft.com/kb/916630/) You can view a child entity that another user creates even if the Share relationship and the Reparent relationship are set to CascadeNone in Microsoft Dynamics CRM 3.0
917109 (http://support.microsoft.com/kb/917109/) No contacts are found if you use the Advanced Find function in Microsoft Dynamics CRM 3.0
917277 (http://support.microsoft.com/kb/917277/) You cannot view sent e-mail messages in Microsoft CRM 3.0
920763 (http://support.microsoft.com/kb/920763/) Some columns in a list view show incorrect data values if these columns have similar names in Microsoft Dynamics CRM 3.0
921653 (http://support.microsoft.com/kb/921653/) The Microsoft Dynamics CRM client for Outlook stops responding when you promote an e-mail message
Additional Issues and Complete list that got fixed with this rollup can also be found out @ http://support.microsoft.com/kb/922815/EN-US/
Hope this helps! - Dipesh