On the subject of the white screen (on PicassoII) with Xamiga24, i have
something to add:
  (maybe it's related or just pure coincidence).
    This afternoon when i started my Amiga i didn't have the workbench on
a Picasso mode, it was set in the prefs as NTSC hires interlaced.Twice i reboot
(starting Amigados and after that launching NetBSD) and started the Xserver and
both times i end up with a white screen .The third time i set a Picasso mode
(800x600) in the prefs and reboot that time when i started the xserver it worked
(screen with garbage first,second ,root tile with X,the applications showed up)

Bye
Michel