SRM PO Transmission duplicated to Supplier

Hi Experts,

We have upgraded from SRM 5.0 to SRM 7.01 and now SRM PO Transmission is being repeated to Supplier after changes are made in ordered PO when it should only sent once.

in the old srm5.0, when I changed the cost center of PO, there will be no transmission fax to the supplier but srm7.0 does....

I added POO 'BBP_PDS_ACC' COST_CTR to the BBPV_COMP_FIELDS. But when I changed the po with the cost center, it triggered the output method to send the fax to the vendor.

Any other advice on this problem ? or is it the SRM7.01's standard behaver of this?

Thanks