Trigger Not Executing CLR Code/stored Proc

I have a database trigger that is set to call a CLR trigger/stored proc when a certain field in a table is updated. The issue is that if i execute the stored proc manually in enterprise studio, it works perfectly but the same call made through the trigger does not go through. A few more details -


I have CLR integration enabled on the sql server.

The dbo has UNSAFE ASSEMBLY rights

I have the both the assembly and the serialized dll imported in the database.


Here's the definition of the stored proc -


CREATE PROCEDURE [dbo].[WriteXMLNotification]

@TaskID [nvarchar](20)

WITH EXECUTE AS CALLER

AS

EXTERNAL NAME [DataInterfaceWebServices].[TaskUpdateXMLWriter.WriteXMLNotification].[run]



and the trigger -



CREATE TRIGGER [dbo].[tr_Task_U]

ON [dbo].[_Task]

FOR UPDATE, INSERT AS

IF UPDATE (TaskType_Status) OR UPDATE (TaskType) OR UPDATE (TaskType_SubType1)

BEGIN

SET NOCOUNT ON;

DECLARE @status AS INT

DECLARE @taskType AS INT

DECLARE @taskSubType AS INT

DECLARE @taskID as sysname

DECLARE @cmd as sysname

DECLARE @parentTask as sysname

DECLARE @NotificationXMLTaskID as sysname



SELECT @status = [TaskType_Status] FROM inserted

SELECT @taskType = [TaskType] FROM inserted

SELECT @taskSubType = [TaskType_SubType1] FROM inserted

SELECT @taskID = [TaskID] FROM inserted

SELECT @parentTask = [Parent_TaskID] FROM inserted

SELECT @NotificationXMLTaskID = [MCCTaskID] FROM _TaskNotificationXML WHERE [MCCTaskID] = @parentTask



IF (@status = 2602) AND (@taskType = 2282) AND (@taskSubType = 19500)

BEGIN

exec WriteXMLNotification @taskID;

END

ELSE IF (@taskType = 2285) AND (@parentTask IS NOT NULL) AND (@NotificationXMLTaskID IS NOT NULL)

BEGIN

exec WriteXMLNotification @parentTask;

END



END


I stepped into the trigger and it seems to execute the line " exec WriteXMLNotification @taskID;" but nothing happens, but if I run that same line manually, it works. Could it be that the impersonation by the EXECUTE AS clause is causing it to fail?

Please advise!

Thanks in Advance,
-Mihir Sonalkar.