the site says it goes up every ten hands. so the same problem is still there. it has nothing to do with stack size or people left.

13. In Single Table Poker Tournaments, players start with either $800 in chips for tournaments with buy-ins less than $50 or with $1000 in chips for tournaments with higher buy-ins. The Levels for these tournaments go up after every ten hands. In Multi-table Poker Tournaments, levels are on a ‘time’ basis and the time may vary depending on the tournament. Play continues until there is a winner.