I found it interesting that Beth said she had her own "agenda" when she went to see Paulus. She has been very vague about details from their meeting other than his sweat.
Beth believes she was kidnapped. She really appears to believe the vdns know something about it.
At this point, with the investigation back at where they started, what would Beth be jeopardizing by telling the media some more of what she knows? Perhaps if she was to reveal a bit more, such as why she thinks Natalee was at the vdS home at 3:15am, it would put some pressure back on the vdS's.