Please note this is an old forum thread. Information in this post may be out-to-date and/or erroneous.
Every phpdocx version includes new features and improvements. Previously unsupported features may have been added to newer releases, or past issues may have been corrected.
And since there's already another hint from another user, the developers might want to check the underscore parsing. That could be the issue. Although with the method above (writing $VARIABLE_NAME$ into notepad then pasting into work) I did manage to have a working table with underscore variables. I'm not sure underscore is the issue, since this 1 row bug appeared for me for non-underscore variables too.