Someone at Ancestry said it was a "looping" problem or maybe a corrupt cookie
Hopefully just a cookie issue.
From your Safari menu bar click Safari > Preferences then select the Privacy tab.
Click: Remove All Website Data
That will remove the cookies.
Quit then relaunch Safari then try ancestry.com
If that didn't help ...
Go to ~/Library/Caches/com.apple.Safari/Cache.db. Move the Cache.db file to the Trash.
For Lion v10.7x: To find the Home folder in OS X Lion, open the Finder, hold the Option key, and choose Go > Library
Try that site again.
edited by: cs
They also had me add a keychain access.
Try this one more time ...
Open Keychain Access /Applications/Utilities
Select Passwords on the left.
Locate then deltete the Ancestry.com keychain
Now type this in the search field: Safari Forms Autofill
Delete that keychain as well.
From the Keychain Access menu bar (top of your screen), click Keychain Access > Keychain First Aid.
Click Verify. If necesssary, click Repair.
Quit then relaunch Safari. Check Safari > Preferences > Autofill. Make sure User names and passwords is selected.
Navigate to the Ancestry site. Click yes when prompted after entering the user name and password. That will create a new kecyhain for you.
If you still have problems, I had the same problem staying logged into that site on Safari as well so I use Firefox. You may want to give that a try as an alternative. Good to have a backup browser installed regardless.
edited by: cs