automessage blog level messages not sending

I've had the automessage plugin installed for about a week with blog level messages set to send immediately and after a 1 day delay. The messages scheduled to send immediately seem to work fine but the one with the time delay hasn't sent anything yet even though there are currently 11 messages in the queue that have been there for many days.

I've tried forcing the queue to process with no luck and I've checked that the message isn't paused.
Any help would be greatly appreciated.