Telldus Scheduler in windows is using Windows Task Scheduler for the actual scheduling. Telldus Scheduler acts as a front end, and adds tasks to Windows Task Scheduler. The tasks are set to run even if you're not logged on, no matter if Telldus Scheduler is in Autostart/Startup or not.
This works fine in for example WIndows XP, but we haven't tried it in Windows Home Server. It would be good if you could examine the created tasks directly in Windows Task Scheduler, or create a task manually and see if that runs when you're not logged in. The same thing about the missing tasks, have they disappeared from Windows Task Scheduler? If so, I have no idea why this could be at the moment.