I'm having the same problem in an as2 banner. Using Flash CS4.
Helvetica Neue Bold 75 will not show up in a dynamic TextField when banner is compiled. If you place the text in the TextField manually it will show up, but when you set the "text" property, nothing shows. When I switch font to other Helvetica 65 it works fine. Switch it to Helvetica Neue Black Extended, font disappears again. When I trace out "text" property of TextField it is set to what I want it to be. In size report the font shows up as being embedded.
I've looked around and people have been having this problem for at least 5 years .
Has anyone come up with either a solution or a reason for this problem?