OK - after doing a test I think I see why the additional tab is opening the site's homepage, and staying open. There doesn't seem to be a valid referrer host, it thinks the referrer is blank.
User goes to the whitepaper page, login, 2nd tab opened, first tab contains download link. 2nd tab contains homepage only. This 2nd tab is supposed to open and prompt user for PDF download, then disappear.
Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/Home.aspx'
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/'
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:49 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Local port is 80. Redirect to HTTPS (https://sitename.com/)
Wed May 20 10:00:49 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:49 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:49 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:49 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Path: '/'
Wed May 20 10:00:49 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test :
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Redirect user to home page (http://sitename.com)
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 1
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/~/media/CE0AD0D9B8FC48A5B247FC102D6A27A0.pdf'
Wed May 20 10:00:49 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:48 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 1
Wed May 20 10:00:48 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:48 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: 'sitename.com'
Wed May 20 10:00:48 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/whitepapers/2015/05/page-path/asset.aspx'
Wed May 20 10:00:48 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:47 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 1
Wed May 20 10:00:47 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:47 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: 'sitename.com'
Wed May 20 10:00:47 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/login/login.aspx'
Wed May 20 10:00:47 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 1
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: 'sitename.com'
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/design/fonts/314569/F77AE15C55FAFC3C5.css'
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/login/login.aspx'
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/whitepapers/2015/05/page-path/asset.aspx'
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/whitepapers/2015/05/page.aspx'
Wed May 20 10:00:39 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :
Wed May 20 10:00:39 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Local port is 80. Redirect to HTTPS (https://sitename.com/whitepapers/2015/05/page.aspx)
Wed May 20 10:00:39 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Contains referer_allowed_hosts: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 0
Wed May 20 10:00:39 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Referer Host: ''
Wed May 20 10:00:39 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test : Path: '/whitepapers/2015/05/page.aspx'
Wed May 20 10:00:39 PDT 2015 info 1600A tmm1[10278] Rule /Common/irule-test :
Download PDF only
Rule /Common/irule-test : Contains referer_allowed_hosts: 1
Wed May 20 10:03:58 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : EndsWith referer_check_filetypes: 1
Wed May 20 10:03:58 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Referer Host: 'sitename.com'
Wed May 20 10:03:58 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test : Path: '/~/media/3397BD0B717641088CD7BEB65879A87C.pdf'
Wed May 20 10:03:58 PDT 2015 info 1600A tmm[10278] Rule /Common/irule-test :