To solve this issue, in file CreateDocx.inc change
line 4285, from:
[quote]header('Content-Length: ' . filesize($fileName));[/quote]
to:
[quote]header('Content-Length: ' . filesize($fileName . '.' .
$this->_extension));[/quote]
We're finishing a new version with this bug solved and some other improvements and new features.
Regards.