Conditions are missing after PO release in ME29N

Hi Gurus

we have created some custom conditions like Transportation, Packing and forwarding and Certification charges for maintaining in PO at both Header and Item level. Here if we are maintaining in Header level the conditions are missing after releasing and saving the PO on ME29N. But for Item conditions there were no issues.

Could anyone suggest me where i have to check for resolving this issue.

Thanks in advance......