Is Tidy installed and active? Please check it and try again after you enable Tidy.
Tidy made a positive difference. Thanks!
It's probably worth mentioning in your 'HTML To Word' documentation page at http://www.phpdocx.com/documentation/html-to-word-PHP that Tidy needs to be enabled for CSS parsing to work. I believe Tidy is already bundled with PHP 5.3, but it's not enabled by default.