I've noticed that the beta site seems to have omitted (or not transferred) some of the profile information from the old website. I notice that the beta didn't transfer my KTN and my middle name. In order to add your middle name to your profile on the beta site you'll need to contact a CSR. You can't do it yourself as it is grayed out. This may be the reason why you are not getting TSA pre-check when booking through the beta site.
Regarding getting your KTN on your ticket when booking through corporate, I've found that even though the site autofills your personal information it always leaves off the KTN. Try clicking on the pull down window that lists the different travelers within your company. Your profile should be in that list, and it seems that when clicking on your name via this pull down list it will populate the KTN in the appropriate field.

Hope this works for you.