bs-dont-show-regexp being ignored

[Shug Boabby]

hello everyone,

i am using the bs- commands for buffer navigation. it has been a
revolution to my daily work. this is my current set-up:

  (setq bs-default-sort-name "by name")
  (setq bs-dont-show-regexp "_region\\.tex_")
  (setq bs-must-always-show-regexp "\\*scratch\\*\\|\\*Python\\*")
  (global-set-key [(control b)] 'bs-show)
  (global-set-key [(control x) (left)] 'bs-cycle-previous)
  (global-set-key [(control x) (right)] 'bs-cycle-next)
  (global-set-key [(control x) (control b)] 'electric-buffer-list)

however... the dont-show regexp is being ignored! i have tried setting
it to many other different file names/regexps, but i can't get it to
work for anything. is it broken? am i setting it incorrectly? is it
working for anyone else?