SQLServerReportingService:有人能解释这种奇怪的行为吗?

虽然我最初计算表中运行的行数的问题已经解决,但我仍然想知道SQL Server Reporting Service中以下行为的起源(希望示例足够清楚):

select 1 AS Column1, 'First' AS Column2
union
select 2 AS Column1, 'Second' AS Column2
union 
select 2 AS Column1, 'Third' AS Column2
union
select 3 AS Column1, 'Fourth' AS Column2
union
select 3 AS Column1, 'Fifth' AS Column2

alt text http://www.freeimagehosting.net/uploads/80536e09f9.png

但是,当我添加一个包含以下内容的文本框:“=”项目数:“+ReportItems(“RowNumber”).Value.ToString”时,下一页的第一个行号出错:

alt text http://www.freeimagehosting.net/uploads/716694d095.png

表的第一个行号与上一页的textbox的值相同! 我没想到会有这种行为,有人能解释为什么会发生这种情况吗?