Gentlemen,
It is picking up somewhere on the MOTS playlist that track had initially generated. If you want your Seed 1 list to start with the song you chose, you actually need to hit < , select that first song, and press GO.
Once you spend some time with the interface, this makes a little more sense. Since the player is essentially a smart randomizer, it only pays attention to ordered lists or hierarchies when you ask it to. If, for example, I choose Eric Clapton from my list and press GO, it will start playing at a random point in the Eric Clapton albums I have collected and continue playing Eric Clapton until the catalog is played through (then it will move to a MOTS list). If, however, I press < to move one layer in and then select a specific album title and press GO, it will play the album in correct track order (and then move to a MOTS list).
When you choose an item* to play and press GO to start the music, you are essentially putting the first seed in place. While that item is playing through, you can choose additional items to add to the que. Once it runs out of requests, MOTS takes over.
*I say item because you can select either an entire artist's catalog, an album, or a single song. Whatever layer of sorting you press GO on is what is put in place. So your first seed, for example, could be all of Robbie Williams' music, while the next item could be a single song by The Who. When you look at your QUEUE, you will see the first item you selected, followed by any other items you added to the queue, followed by the MOTS list as denoted by the vertical blue line.
Hopefully this clears it up!
There is scarcely anything in this world that some man cannot make a little worse and sell a little more cheaply. The person who buys on price alone is this man's lawful prey. - John Ruskin