External debugging - SAP SRM 7.0

Hello.

I'm working with SAP SRM 7.0.

I need to debug a FM that is getting a dump and I need debug to find the error.

To do this, I'm trying debugging it, creating an external break in SRM FM (SE38).

Then we logon in SRM webpage and try to create a purchase order.

But when click save or verifying, break doesn't initiate.

thanks.

Glauco