problemi with simple ya-snippets

[Luca Ferrari <fluca1978@infinito.it>]

Hi all,
I'm trying to configure  a couple of simple snippets for PHP, as follows:

# name: foreach ... { ... }
# key: fore
# --
foreach ( \$${1:array} as \$${2:current_element} ) {
    $0
}


# name: foreach ... { ... }
# key: kfor
# --
foreach ( array_keys( \$${1:array} ) as \$${2:current_key} ) {
    $0
}


stored respectively into the snippets directory as php/fore and php/kfor.
After that I do yas/reload-all and try my new snippets. Pressing tab
has no effect, while calling M-x yas-expand works for the fore snippet
but not for the kfor. Any idea about what am I missing?
I'm running yasnippet 0.8 installed via elpa on emacs 24.3.1.

Thanks,
Luca