Am I hitting a bug?

Hi group,

I have a document with the following DOCTYPE def:

<!DOCTYPE abc:document SYSTEM "abcdtd_v03_09.dtd">

When I call BaseMarkupSerializer.startDTD("abc:document", null, "
c:\\abcdtd_v03_09.dtd"), it strips off the prefix and just writes
"document" as the root tag name.
Am I hitting a known bug or I am missing something?
Is there some workaround like turning on some feature?

Please advise.
Regards,
Ravi Ranjan Jha