Problem using construct_usercp_nav and phrases

[nnStaff]

I am tweaking an old plugin that worked just fine in 3.8.x, for 4.0. The plugin is running out of misc.php, and calling construct_usercp_nav. Strange thing though, about 1/3 of the phrases used to construct the menu are empty, so it's not constructing the full menu. I've double and triple-checked the code and it isn't setting $vbphrase anywhere, so I don't know if it's somehow not caching the phrases, or if they're somehow getting blanked out.

Is it possible I need to "enable" these phrases? How is it that some work and some don't?

--------------- Added [DATE]1269483763[/DATE] at [TIME]1269483763[/TIME] ---------------

edit: here's a snapshot of what I'm talking about. If you compare that to a typical, admin usercp, it's missing several entries. If you look at the source code, all the code to generate the full menu is there, but there are blanks where the text should be, hence the vbphrase is not working