If you get nowhere with him there is a work-around you could make. But it does require hacking Zenphoto.
add the following to functions-basic.php
`
function ngettext($msgid1,$msgid2,$n) {
if ($n==0 || $n>1) {
return $msgid2;
}
return $msgid1;
}
`
Seems your install has the `gettext()` function so we do not load the alternate implementation, but it does not have the `ngettext()` function so it fails. The above is the alternate for that function. Note, though, that translations will not work in some cases (where `ngettext()` is used.