Rate is changing after quantity is changing

[JayaLakshmiJilakara]

I created one record in sales Order and for that respective sales order i create one delivery note, In delivery note i changed the quantity of the item and i delete the entire record in delivery note

Again i created one more record in Sales order and for that respective sales order i create delivery note, In delivery note i changed the quantity of the item(At this time ,rate is 200) and after saving the record it is showing rate as 300.

Please help me, to solve this problem.

[ganureddy]

check if any pricing rule are created against item, in pricing rule list

[JayaLakshmiJilakara]

I am experiencing issues with functions being triggered every time I change the quantity in the delivery note. How can I resolve this?