**Note - I have found a fix for some users. Check back on Monday and all will be revealed.
It seems that for some users scheduling posts in Wordpress does not work in versions 2.5 and higher. This problem does not occur for all users and seems to be related to the web host they are using and possible security settings. Ultimately, however, the problem is in Wordpress as scheduled posts worked in earlier versions.
It is my understanding the the problem may be with the cron.php file that is in the wp-includes folder. Cron jobs deal with scheduled events and for some reason this file is not communicating properly with the server.
There is not simple fix or solution to this problem. Some fixes work for some users but not for others. I know of two people using the same webhost who currently can not schedule a post. Well, the can schedule it and set the time but when the time to publish arrives it doesn't publish and the time starts counting backward. For example, a post is scheduled for 4:40PM. That time passes and 10 minutes later it will say scheduled to post on 10 mins. Forty minutes later it says scheduled to post in 40 minutes. The scheduled post, however, is never published until it is done manually.
