Send PDF (PDF Architecht) Attached EMAIL NAV 5.0 CORRUPTED

When I try to send and email using CU Email the first time its OK, but when I try to do next times, the process runs ok but the PDF attached (xx.pdf) it's blanck there's nothing(open with notepad, 0 KB) in the file and you cant open because there nothing inside.

NAV 5.0 and Outlook 2007


Thanks.