LESSC @font-face error

I have a little LESS mixin for simplifying font face stuff

.fontface(@font){
    @font-face {
        font-family: '@{font}';
        src: url('../fonts/@{font}.eot');
        src: local('☺'), url('../fonts/@{font}.woff') format('woff'), url('../fonts/@{font}.ttf') format('truetype'), url('../fonts/@{font}.svg#webfont5SwbW1jA') format('svg');
        font-weight: normal;
        font-style: normal;
    }
}

On my local computer (OS/X), running lessc on

.fontface(@font){
    @font-face {
        font-family: '@{font}';
        src: url('../fonts/@{font}.eot');
        src: local('☺'), url('../fonts/@{font}.woff') format('woff'), url('../fonts/@{font}.ttf') format('truetype'), url('../fonts/@{font}.svg#webfont5SwbW1jA') format('svg');
        font-weight: normal;
        font-style: normal;
    }
}

.fontface('MyFont');
.fontface('MyOtherFont');

returns

@font-face {
  font-family: 'MyFont';
  src: url('../fonts/MyFont.eot');
  src: local('☺'), url('../fonts/MyFont.woff') format('woff'), url('../fonts/MyFont.ttf') format('truetype'), url('../fonts/MyFont.svg#webfont5SwbW1jA') format('svg');
  font-weight: normal;
  font-style: normal;
}
@font-face {
  font-family: 'MyOtherFont';
  src: url('../fonts/MyOtherFont.eot');
  src: local('☺'), url('../fonts/MyOtherFont.woff') format('woff'), url('../fonts/MyOtherFont.ttf') format('truetype'), url('../fonts/MyOtherFont.svg#webfont5SwbW1jA') format('svg');
  font-weight: normal;
  font-style: normal;
}

however running it on our build server (CentOS 6.2) returns

@font-face {
  font-family: 'MyFont';
  src: url('../fonts/MyFont.eot');
  src: local('☺'), url('../fonts/MyFont.woff') format('woff'), url('../fonts/MyFont.ttf') format('truetype'), url('../fonts/MyFont.svg#webfont5SwbW1jA') format('svg');
  font-weight: normal;
  font-style: normal;
}
@font-face {
  font-family: 'MyFont';
  src: url('../fonts/MyFont.eot');
  src: local('☺'), url('../fonts/MyFont.woff') format('woff'), url('../fonts/MyFont.ttf') format('truetype'), url('../fonts/MyFont.svg#webfont5SwbW1jA') format('svg');
  font-weight: normal;
  font-style: normal;
}

Why are both mixins returning the same on our build server but working fine locally?

Both computers report the same less version.

Sams-MacBook-Pro:Desktop sr$ lessc -v
lessc 1.3.0 (LESS Compiler) [JavaScript]


[sr@egdjnk01 ~]$ lessc -v
lessc 1.3.0 (LESS Compiler) [JavaScript]

I've run npm -g update less on both, but I'm still receiving different behavior.

I think it's something to do with @font-face, if I remove that and replace it with a dummy class name the output is fine.