Thanks for pointing this out. It looks like there's a minor coding issue in our XML file. Can you edit the /modules/mod_sendy/mod_sendy.xml file. Around line 11, you'll see:
<![CDATA[LOTS OF STUFF HERE]]>
Delete that <![CDATA .. line entirely. There's an open div in there that needs to be closed but, for now, it's simpler to just remove it entirely.
Let us know if that helps and, if so, we'll release an updated package.
I went ahead and added the missing div. I had to do the same for plugin/user/sendy/sendy.xml and plugin/system/sendy/sendy.xml, so you might want to update all three.
I also used the sendy docs to create my own newsletter signup form using RSForms. This allows me to add the name field to pass to the Sendy database. Everything appears to be working properly. Thanks again for your help.