EML

As per question 10. in the FAQ's
"How can I get my existing metadata into EML?" ... "Case 3: If your metadata is already in XML but in some other form such as NBII or FGDC use the following conversion method..." The suggested method is to write an XSLT script to do the conversion. Although this may be possible, I am trying to save some time by using an Altova product (Mapforce) to do the conversion. It will essentially create the XSLT to do the conversion; however, it will only work with valid schema definitions or DTD's as input and output. There is no problem using the NBII DTD as input or output, however there are many errors when trying to validate the EML schemas. Is this a problem that has been observed by others that is occuring only with the validation done using Altova products, or is the problem with the eml schema definitions themselves?