Problem with SMIL 3.0 DTD (attribs backgroundOpacity external entity)

Hello SMIL people,

jaxb-dtd-parser at GitHub (https://github.com/eclipse-ee4j/jaxb-dtd-parser)
had an issue when testing the program by using SMIL 3.0 DTD. It found a
problem with this entity declaration:

www.w3.org/2008/SMIL30/smil-attribs-1.mod

<!-- add one &#38; for each level of indirection -->
  <!ENTITY % SMIL.backgroundOpacity.attrib "
   %SMIL.pfx;backgroundOpacity     CDATA    '100&#38;#38;#38;#37;'
  ">

jaxb-dtd-parser doesn't expect &# by parsing each DTD available here. Would
it be correct fixing entity declaration removing unnecessary characters?

<!-- add one &#38; for each level of indirection -->
  <!ENTITY % SMIL.backgroundOpacity.attrib "
   %SMIL.pfx;backgroundOpacity     CDATA    '100#37;'
  ">

Regards,
Antonio.