A customer just reported this issue:
http://www.mjtnet.com/usergroup/viewtopic.php?p=17969
Seems Kaspersky must be intercepting emulated keystrokes and is slowing their progress. I’ve emailed Kaspersky to ask for a resolution. Until then if you are running Kaspersky Internet Suite you need to close it down completely to prevent this issue.
Quite rightly you should be running a security solution. We run AVG Antivirus and Webroot Spy Sweeper on our machines here. Neither affect Macro Scheduler in any way.