Perhaps you can do something with this. You can find the whole thread on http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=6216.

CREATE PROCEDURE crosstab 
@select varchar(8000),
@sumfunc varchar(100), 
@pivot varchar(100), 
@table varchar(100),
@where varchar(1000)=null
AS

DECLARE...

The performance of the load is not the problem.

I just want to know why the difference is so much: from 6000/second to 250/second.

Is it possible that this is only because...

Thanks Pedro.

But what I don't understand:

with the clustered PK and the nonclustered index: it becomes slow.

with the clustered PK and without the nonclustered index: it is always fast.

I have the same error when I add an attachment.

Something seems to be known by Microsoft. See http://support.microsoft.com/kb/910416