The situation is different for Poser 4 - there, although the hard coded limit is 256, the file names often start getting truncated well before that point. Other than organising your library better, there's no cure. :) PBooost won't get around the 256 item limit, it just enables you to move stuff "out of the way" when you aren't using it. I use a similar system, but it's manually operated with the help of P3dO Explorer.