Deduction in Absence Quota!

Dear experts!

I have anther weird cases as below:

My employee applied Paid Leave from 2-Jan-2010 to 31-Jan-2010 ( 30 days), but total Paid Leave entitlement just 28 days, so the first Absence Quota in IT2006 is negative deduction. It's correct, no problem. I understand this point.

But my problem is total deduction in the first Absence Quota negative total isn't 2 days ( 28-30 =-2), actually maybe due to mistake of enduser the Absence Quota negative deduction is 8 days ( bigger than 6 days). I don't know why.

In my case the first Absence Quota Number is 5 days and Deduction is 13 days. Although the correct Deduction value just 7days (28-30 = -2 days).

And when I use standard report: PT_QTA10 - Absence Quota Information, it just show 7 days, not 13 days as deduction. Thus I guess that 6days is not deducted by user inputted Paid Leave in IT2001. Because if deducted through IT2001, this standard report will count 6 days as DEDUCTION. And of course they could not change directly in IT2006 because this field is just display. Thus I'm really confuse.

Have u ever had this case? Could you please give me some advices? You know now it's 2011 so we cannot ask enduser what did they do in Jan 2010.

Regards!

Woody.