Samuel,
i think that by default, Org no longer listens to, e.g., =<s[TAB]=.
but, if you load =org-tempo=, it still does. i wonder if you might see
if you are loading =org-tempo= (maybe [C-h v org-modules]), disable
that, and see if that clears away some of the underbrush.
(you can get something like the old behavior with =C-c C-,=.)
i use yasnippet to expand =<le[TAB]=.
----
# key: <le
# name: latex equation environment
# --
\begin{equation}
$0
\end{equation}
----
and, that works for me.
if i re-format your snippet (maybe this was the original formatting?)
----
# name: src
# key: <s
# --
#+BEGIN_SRC $1
$0
#+END_SRC
----
and open an org file, =<s[TAB]=, it seems to work if i enter a language
name and then =[TAB]= to commit. if i commit with =[RET]= instead, it
still *seems* to work (in terms of the buffer contents), but i get this
message
----
[yas] Committing snippets. Action would destroy a protection overlay.
----
i didn't run into any lisp errors.
in case any of that helps.
cheers, Greg
