cnd parser error with a valid cnd.

[dbu]

from https://github.com/symfony-cmf/MediaBundle/pull/63/files it seems this cnd works:

<cmf = 'http://cmf.symfony.com/phpcr/1.0'>
[cmf:mediaNode] > nt:hierarchyNode, cmf:media

[cmf:media] mixin
   - description (string)
   - copyright (string)
   - authorName (string)
   - metadata (string)
   - metadataKeys (string)

[cmf:image] > cmf:media mixin
   - width (long) mandatory
   - height (long) mandatory

while this one does not

<cmf = 'http://cmf.symfony.com/phpcr/1.0'>

[cmf:media] mixin
   - description (string)
   - copyright (string)
   - authorName (string)
   - metadata (string)
   - metadataKeys (string)

[cmf:image] > cmf:media mixin
   - width (long) mandatory
   - height (long) mandatory

[cmf:mediaNode] > nt:hierarchyNode, cmf:media