I've gone through the forums and I realize this seems to be an intermittent issue. This only started happening a few days ago, I started experiencing some problems and I'm beginning to think they are related:
1) Scheduled Posts are no longer publishing. WP recognizes this and flags as a Missed Schedule Time. Posted are being creating in WP - not Windows Live Writer.
2) When I manually publish the failed scheduled post to the intended URL, I could not access. Browsers (FF,Chrome & Explorer) all indicate the site has gone into an infinite loop. I don't use any redirection (plugins or at hostlevel). If I go back into WP and manually change the URL to an new address, the post works. After moving the post's URL and republishing, the old URL redirects to the very first post in that category instead of a 404 page. The original URL is not referenced in any other posts (trash is empty) so I don't understand where that redirect is coming from.
3) Then, yesterday, I couldn't access wp-admin, but the site was still up. Got a Memory Exceeded error. Guess what? Trying that broken URL from the post that was redirecting ALSO was now giving me a Memory Exceeded error.
I followed forum advise and FTPed all the plug-ins out, then got back into WP Dashboard. The issue appears to be with either W3 Total Cache and WP-DBManager. I've uninstalled both. Still scheduled posts won't work. Broken URL now goes back into a redirect to the very first post. You can try yourself here: http://shmortgage.com/zh-hant/2012/08/hrw-10/.
Here is the final piece: I attempted to download into WAMPServer to see if I could figure it out. Was advised the max packet size was exceeded and couldn't import.
The exact line is in wp_options, option_name chron. In a clean WP install, that otion_value is 805 characters in length. On my live site, it's 1,866,045 characters in length. It just repeats over and over.
Any ideas on how to fix that?