Ah, I see now. No, it's not a bug. In your layout, change the <tables> token to <currenttables>. The <tables> token displays the optimal table layout, given tables all of a particular size (which is, by default, 10). The <currenttables> token displays what the actual current layout is.
I'm sure that when your tournament is running and you see on the main (tournament) page "10 x 1", if you then move to the Tables tab or the Seating Chart page, you'll see that you still have players seated at two tables of 7 seats each. After you change the token to <currenttables>, you should see 6 x 2, and then 6 x 1 5 x 1, and then 5 x 2, etc, as players bust out.