One thing I noticed on my Firefox (version 18.0.2) is that when I searched for a person in my tree using the upper right box, the listings were double-spaced and I was getting the "check back soon" error a lot today.
When I cleared the cache and cleared cookies for only Ancestry, both problems went away.
For instructions on clearly selected cookies in Firefox, see http://support.mozilla.org/en-US/kb/delete-cookies-remove-in...

Barbara