First thing I'd look at would be creating a Common Table Expression for the invoice line item totals using the filter. That way you have a cursor that contains only totals for the record you want and can inner join against that and take the where clause out of the main expression.

(I'm gonna do this very fast to show what I'm talking about so forgive boneheaded typos etc )

;WITH cte as 
 (SELECT ivd_invfk, SUM(ivd_amount) as invtotal FROM InvoiceDetails 
WHERE ivd_invfk NOT IN (SELECT crt_invfk 
						FROM CashReceipts 
								INNER JOIN Deposits on crt_depfk = dep_pk 
						WHERE dep_date <= @crt_date)
GROUP BY ivd_invfk
)
	SELECT [inv_awbfk],
		[inv_cancelled],
		[inv_cusfk],
		[inv_cusnumber],
		[inv_date],
		[inv_goodsvalue],
		[inv_insurance],
		[inv_number],
		[inv_pieces],
         	[inv_pk],
		[inv_printed],
		[inv_weight] 
		,cus_company
		,cus_lastname
		,cus_firstname
		,cus_number
		,cnt_code
		,inv_total = cte.invtotal
		,awb_number
		,asatdate = @crt_date
	FROM [dbo].[Invoices]
              INNER JOIN cte on invoices.inv_pk = cte.ivd_invfk
		INNER JOIN Customers on inv_cusfk = cus_pk
	       INNER JOIN AirWayBills on inv_awbfk = awb_pk
		INNER JOIN Countries ON cus_cntfk = cnt_pk
	
	ORDER BY inv_number

Makes sense?



>I'm using the following in a Stored Procedure to pull out some data for a report. Unfortunately it's running too slowly and timing out when I call the Dataset.Fill().
>
>

	SELECT [inv_awbfk],
>		[inv_cancelled],
>		[inv_cusfk],
>		[inv_cusnumber],
>		[inv_date],
>		[inv_goodsvalue],
>		[inv_insurance],
>		[inv_number],
>		[inv_pieces],
>		[inv_pk],
>		[inv_printed],
>		[inv_weight] 
>		,cus_company
>		,cus_lastname
>		,cus_firstname
>		,cus_number
>		,cnt_code
>		,inv_total = (SELECT SUM(ivd_amount) FROM InvoiceDetails WHERE ivd_invfk = inv_pk)
>		,awb_number
>		,asatdate = @crt_date
>	FROM [dbo].[Invoices]
>		INNER JOIN Customers on inv_cusfk = cus_pk
>		INNER JOIN AirWayBills on inv_awbfk = awb_pk
>		INNER JOIN Countries ON cus_cntfk = cnt_pk
>	WHERE inv_pk NOT IN (SELECT crt_invfk 
>							FROM CashReceipts 
>								INNER JOIN Deposits on crt_depfk = dep_pk 
>							WHERE dep_date <= @crt_date)
>	ORDER BY inv_number

>
>Any suggestions for speeding this up?
>
>I've got indexes on all the joined fields.
>
>Is there a way for me to post the execution plan here?