group and ungroup sum

[xponcall]

I have the following:

Select t0, t1,t2,t3,t4,sum(x1)as tx1,sum(x2)tx2
into tbl2 From Tbl1
Group by t0,t1,t2,t3,t4
Having (sum(x1)+sum(x2))> 10

trying to ungroup the above by flaging the tx column to 'Y':

update a set a.tx='Y'
from tbl1 a inner join tb2 b
on a.t0=bt0 and
a.t1=b.t1 and
a.t2=b.t2 and
a.t3=b.t3 and
a.t4=b.t4

select t0, t1,t2,t3,t4,x1,x2
into tbl3 from tbl1 where tx='Y'

trying to get these value to be the same:

select sum(tx1),sum(tx2) from tb2
select sum(x1), sumx(2) from tb3

However the sum for both table are different. Anyone have any suggestion?

thanks