Which version of Connections and Link do you have installed? Make sure you have the latest of both. Connections, the latest is 0.8.14 and Link the latest is 2.0.2. I believe there was, very briefly, a version, where the CSS was not being loaded correctly on the Link admin page, but that was fixed.
Now, the only other time I’ve seen this happen I think it was either the theme or another plugin which did not limits its CSS to its own admin pages. Have you tried deactivating other plugins.