Backtrace and message buffer tell me different things

[Lennart Borgman <lennart.borgman@gmail.com>]

I get a strange error from mumamo. The backtrace looks like this:

Debugger entered--Lisp error: (error "Selecting deleted buffer")
  byte-code("..." [buffer table set-syntax-table] 2)
  #[(body) [strange stuff here...]
  mumamo-fetch-major-mode-setup(mumamo-bad-mode nil)
  mumamo-get-major-mode-setup(html-mode)
  mumamo-new-create-chunk(((1 192 html-mode nil nil nil
(mumamo-chunk-xml-pi mumamo-chunk-alt-php mumamo-chunk-alt-php=
mumamo-chunk-inlined-style mumamo-chunk-inlined-script
mumamo-chunk-style= mumamo-chunk-onjs=) nil nil t) (nil nil nil 0
nil)))
  mumamo-find-chunks-1(192 "mumamo-get-chunk-save-buffer-state")
  mumamo-find-chunks(192 "mumamo-get-chunk-save-buffer-state")
  mumamo-get-chunk-save-buffer-state(192)
  mumamo-turn-on-actions(lisp-interaction-mode)
  html-mumamo-mode()
  call-interactively(html-mumamo-mode t nil)
  execute-extended-command(nil)
  call-interactively(execute-extended-command nil nil)

However in the message buffer I have this:

  MU:returning from mumamo-fetch-major-mode-setup
  MU:after mumamo-fetch-major-mode-setup B
  Making parse-sexp-lookup-properties local to *scratch* while let-bound!
  Entering debugger...

It looks like the debugger think I have not exited
mumamo-fetch-major-mode-setup while the message in the message buffer
says I have done so.

Anyone has any idea of what might be going on here?

This is with my patched version, but I can't see I have any changes
that could be involved here. (I had some before in buffer.c and eval.c
but not any more.) The checkout is from 2010-10-19.