Invalid image specification

[Hans Halvorson]

Emacs 23.0.60.1, CVS from May 14, 2008.  I get the following sorts of
errors at random intervals: (In this case, it occurred when opening a
message in Wanderlust.)  I would be grateful for any advice on finding
the source of this problem.

Debugger entered--Lisp error: (error "Invalid image specification")
  image-mask-p((holiday-hebrew-rosh-hashanah nil "23.1"))
  #[(bind) "ĉ\n���==r=\n8:�===\n��=r==\"�=r :�r    @�==r= @!�r= 
�E==r=        !�=S=!�X==\"=\n!=\n8:�g==h=\n�==#�)\n*�" [plist 
image-exp bind image nil menu-item 4 5 plist-get :image fboundp 
display-images-p eval image-mask-p append (:mask heuristic) copy-sequence 
plist-put] 5]((new-file menu-item "Visit New File..." find-file ([24 6] . "  
C-x C-f") :enable (menu-bar-non-minibuffer-window-p) :help "Specify a new 
file's name, to edit the file" :image (tool-bar-find-image (if ... ... ...))))
  mapcar(#[(bind) "ĉ\n���==r=\n8:�===\n��=r==\"�=r  :�r    @�==r= 
@!�r= �E==r=        !�=S=!�X==\"=\n!=\n8:�g==h=\n�==#�)\n*�" 
[plist image-exp bind image nil menu-item 4 5 plist-get :image fboundp 
display-images-p eval image-mask-p append (:mask heuristic) copy-sequence 
plist-put] 5] (keymap (new-file menu-item "Visit New File..." find-file ([24 6] 
. "  C-x C-f") :enable (menu-bar-non-minibuffer-window-p) :help "Specify a new 
file's name, to edit the file" :image (tool-bar-find-image ...)) (open-file 
menu-item "Open File..." menu-find-file-existing (nil) :enable 
(menu-bar-non-minibuffer-window-p) :help "Read an existing file into an Emacs 
buffer" :image (tool-bar-find-image ...)) (dired menu-item "Open Directory..." 
dired ([24 100] . "  C-x d") :enable (menu-bar-non-minibuffer-window-p) :help 
"Read a directory, to operate on its files" :image (tool-bar-find-image ...)) 
(kill-buffer menu-item "Close" kill-this-buffer (nil) :enable 
(kill-this-buffer-enabled-p) :help "Discard (kill) current buffer" :image 
(tool-bar-find-image ...)) (save-buffer menu-item "Save" save-buffer ([24 19] . 
"  C-x C-s") :enable (and ... ... ...) :help "Save current buffer to its file" 
:image (tool-bar-find-image ...) :visible (or buffer-file-name ...)) 
(write-file menu-item "Save As..." write-file ([24 23] . "  C-x C-w") :enable 
(and ... ...) :help "Write current buffer to another file" :image 
(tool-bar-find-image ...) :visible (or buffer-file-name ...)) (undo menu-item 
"Undo" undo ([31] . "  C-_") :enable (and ... ... ...) :help "Undo last 
operation" :image (tool-bar-find-image ...) :visible (not ...)) (cut menu-item 
"Cut" ("Delete text in region and copy it to the clipboard" ... . 
clipboard-kill-region) :image (tool-bar-find-image ...) :visible (not ...)) 
(copy menu-item "Copy" ("Copy text in region to the clipboard" ... . 
clipboard-kill-ring-save) :image (tool-bar-find-image ...)) (paste menu-item 
"Paste" x-clipboard-yank :enable (not buffer-read-only) :help "Paste (yank) 
text most recently cut/copied" :image (tool-bar-find-image ...) :visible (not 
...)) (search-forward menu-item "String Forward..." 
nonincremental-search-forward (nil) :help "Search forward for a string" :image 
(tool-bar-find-image ...)) (print-buffer menu-item "Print Buffer" print-buffer 
(nil) :enable (menu-bar-menu-frame-live-and-visible-p) :help "Print current 
buffer with page headings" :image (tool-bar-find-image ...)) (customize 
menu-item "customize" customize :image (tool-bar-find-image ...) :help "Edit 
preferences (customize)") (help menu-item "help" #[nil "�!�" 
[menu-bar-help-menu popup-menu] 2 nil nil] :image (tool-bar-find-image ...) 
:help "Pop up the Help menu")))
  tool-bar-make-keymap(ignore)
  key-binding([tool-bar] t)