No, only 38 folders under Characters. I can still add new folders; they'll work. But the PhilC folder doesn't, and never has. It won't open in the Library.

I don't know what my machine has against PhilC, but its opinion is not a reflection of my own.

I think I've finally figured it out, however. Listen carefully. The boxer shorts .zip has a text file named:

if_you_can_not_read_the_html_file_then_here_is_the_text_version.txt

No, really. I'm not making this up.

In my anal-retentive dragon manner, I keep all the readme's bundled with associated files in the Libraries, so I can easily identify the author if necessary. The text-file-with-a-needlessly-long-name was in the PhilC folder all this time. And apparently, that's what has been freaking Poser out. I moved the text file out of the PhilC folder, and suddenly all was sunshine and lollipops. I create a very-long-name file in another folder, and suddenly that folder has dropped into a dark abyss that Poser cannot penetrate.

So watch those filename lengths, everyone. They're evil.