Comment 3 for bug 498623

Status update:

I've removed the following call to set-buffer-multibyte in the 8.1.x branch:
   vm-mime.el:4609: (set-buffer-multibyte nil))

This call is o.k., it is followed by erase-buffer:
   vm-save.el:65: (set-buffer-multibyte nil))

Leaves us with the following four, line numbers are for revision 746 in the 8.1.x branch:
   vm.el:139: (set-buffer-multibyte nil))
   vm-mime.el:321: (and vm-fsfemacs-p (set-buffer-multibyte t))
   vm-mime.el:1948: (and vm-fsfemacs-mule-p (set-buffer-multibyte t))
   vm-reply.el:981: (set-buffer-multibyte t)))