Table DDTNK Updated : Wage type Amount Reduced

Dear All,

I am getting an issue.I am putting amount rs.6000 in one WT3092(Deduction wage type in IT0015).

If deduction is more than earning WT 3092 amount get reduced to   5,374.52-.

DDTNK tbale update like this

WT 3092     - 625.48

This is happening in function PRPRI

Note : There is no retro for this employee.

Both tables DDTNK & ARRRS updated with amount 625.48

What is the issue ?

Regards,

VJ