The development version of XML::Twig (at http://xmltwig.com/xmltwig nearly fixes this: the brackets are there, but the first entity declaration is not output properly (it comes out as <!ENTITY HTMLlat1 SYSTEM "../CCI-DTD/xhtml-lat1.ent" PUBLIC "-//W3C//ENTITIES Latin 1 for XHTML//EN" >). The other 2 are output properly, which is quite puzzling. This occurs whether keep_encoding is used or not. I'll fix it and report back.

I have refactored the code that outputs the internal DTD in the new version, so tests are welcome. Apparently my test suite did not cover this case, so I will add a test too.

Thanks for the info.