We're still in the process of setting up our system and are in the final stages...scheduling.
Just created (or rather edited the Template) a clock in AT, and put at the top of the hour a Link (after previously adding all Music carts as Songs, and most of the jingles as Links). When I scheduled this clock for every hour, every day, for the next month (just as a start), it reported that "Cart X is scheduled but is missing". However, it appears in Myriad's log correctly and plays OK. The carts in question (it's not always the same one) were included when added as Links.
It's only a minor problem, as Myriad is playing them anyway - just curious.