Ted got a job in marketing.
Alvin and the Chipmunks
Dave arrived late for a meeting he was part of, due to (though he did not know this), driving the Chipmunks home. During the meeting, Ted pointed out that kids being sad wouldn't be a good marketing technique. Dave tries to participate in the meeting, but the Chipmunks continue to cause trouble, first by calling Dave about issues at home, and also by drawing on his presentation. Gail ultimately fired Dave as a result. It is likely that he understood the situation after the Chipmunk's rise to fame.