yasnippet placeholder problems

[Julien Cubizolles]

I can't jump anymore from one placeholder to the next with some of my
snippets. Here is an example of such a snippet:

--8<---------------cut here---------------start------------->8---
# -*- mode: snippet -*-
# name: Vitesse
# key: vit
# --
\Vitesse{$1}{$2} $0
--8<---------------cut here---------------end--------------->8---

I also get this message when opening the snippet file:

--8<---------------cut here---------------start------------->8---
font-lock-fontify-keywords-region: Symbol's function definition is void: 
font-lock-preprocessor-face
--8<---------------cut here---------------end--------------->8---

What is even stranger is that the problem is intermittent: the error
message isn't displayed if I try to open the file immediately after and
the placeholder jumping works if I reload the snippet from the file
buffer just after...

Any idea what's going wrong ?

I'm using running GNU Emacs 24.3.50.1 and yasnippet 20130218.2229 from
github.

Julien.