Hi Jason ,
I attached some documents that docx4j fails to convert and in some documents content loss is also there . Later i found that docx4j fails to handle ,if we apply any styles to P (We can apply styles to P ,by clicking the styles from style tab present at top right corner of MSWord2007 ).The equivalent xml for above style is "< w:pStyle w:val="NoSpacing >" . Like this, lots of p styles ...