Did you use 1and1’s “one-click installation” to set yourself up? If so, that’s your issue. 1&1 uses multi-site for their 1-click installs. Which basically mens you could have gotten a free wordpress.com account instead – it’s the same thing. You can’t add new plugins or themes, and you can’t backup your own database. You have to email them and ask them to install and activate them for you.
if you used the 1 click install, I’d suggest installing it yourself, manually, and ‘porting over the posts (provided they haven’t disabled your ability to export).
I only say this form previous experience with 1&1. After running into this issue with clients several times 3 years ago, I stopped working with them. but I’m guessing if the 1-click install is the case with you, they haven’t changed their tactics any.
