issue with MD04

Hi All.

I am ruuning MD04 trasacation.

When i entered material and Plant detail and goes into further screen. When I click on Vendor button vendor details are not populting. I have two diefferent materail number with same plant code. Vendor details are not pupulting for one material and for other material vendor details are populting.

I have mainted source list and PIR but still not able to get the vendor details on the MD04 screen.

Please helpus