Rounding issue for CNY orders

Hi Gurus,

For of free charge sales order with the currency CNY the system is showing the netvalue as 0,01CNY which is wrong.In Item conditions tab the base price is 101,64 CNY and we are maintaining DIF1 condition type for rounding off the value.currently for the qty 25 and the price 101,64 the DIF1 condition value is showing 0,01CNY, and net value 0,01CNY.if I changed the qty or price then the system is showing correct value which is Zero.So the issue is happening in some cases only. Please help me on rectifying this problem.

Regard,

hari challa.