If you receive an error message about enabling cookies while trying to login, try clicking on the login link in the upper right-hand corner, rather than filling in the boxes on the front page immediately.  Using that login link seems to work around this issue.  If you are using Internet Explorer, go to Tools - Internet Options.  Click on Advanced. On the next screen, make sure that Override automatic cookie handling is checked.  Also, make sure that Accept First party cookies is checked.  Finally, Always allow session cookies MUST be checked.  This may need to be done on any computer that you use.