in install.txt installation instructions number two it reads:

2. download Xinha from http://xinha.python-hosting.com/wiki/DownloadsPage
and unpack it into your htmlarea module directory. This should create a
folder named "xihna", "xinha-nightly" or "xihna-latest" within the
"htmlarea" folder.

xinha is spelled wrongly (xihna), which took me some time to figure out when I was creating the folder to drop the files in, thought it would be nice to mention. Thanks!