Links on E2 pages being viewed by people who are not logged in under a domain name other than 'everything2.com' all point to the 'everything2.com' domain. This is so that Google and its ilk will index E2 pages under the One True Domain. This is done by providing a base element in the header of pages served to Guest User.
So that search machines index the One True URL, Guest User is also served a meta element indicating the canonical url of a page.
The base element also affects the log-in form on the front page and a few others that are cached in the server and therefore do not know which domain they are currently being viewed under. If you should need to log into a different domain, go to a lesser-used page and log in there. Use of alternate accounts is generally discouraged by our Insect Overlords. Be yourself.