I believe fixes Leo's problem (at least, I don't see it here).
The patch adds "acronym completion" to PC-do-completion for both
symbols and filenames, and within-word completion to
PC-lisp-complete-symbol.  "Acronym completion" means that
e.g. "mvbl" expands to "make-variable-buffer-local", and
"emacs/lisp/wee" to "emacs/lisp/wid-edit.el".  Partial completion
behavior is fairly complex, so would current users please test
this and let me know if it disturbs other behaviors they have
come to expect?  Thanks,

/s

2007-07-16  Sean O'Rourke  <sorourke@cs.ucsd.edu>

	* complete.el (PC-lisp-complete-symbol): complete symbol around
	point.
	(PC-do-completion): Add "acronym completion" for symbols and
	filenames, so e.g. "mvbl" expands to "make-variable-buffer-local".