Help Me Using Networkday for Counting SLA

[Vidi]

Dear All,

Kinda have problem with counting time between date.
I really need to count time between submit date and resolved date but excluding weekend.
Problem is I never get a constant result with all reference in the other thread.
I always get some error in some row.
For Example :

9/22/2011 15:21 9/23/2011 10:20 2.98
I used = (NETWORKDAYS(A14,B14)*$J$2) + (($I$2- MOD($A14,1))-($I$2-MOD($B14,1)))*24 - ((MOD(A14,1)>MOD(B14,1))*8)

Reference :
I2,J2
Day End Hours per day
17:00 8

I used Excel 2011.
Can somebody help me with this ...
So desperate ...

I attached somedata from worksheet
Really appreciated for any response