Download

In the newbie lesson "Downloading Music", the featured word is introduced as 4th tone and 3rd in the introduction. Then, when read in the dialogue, it's the 4th and 4th. Plus, if you read the pin yin, it's written as 4th and 4th. Is this a mistake or just 2 different ways to pronounce it? I looked up the word in my dictionary and it is xia4 zai3, again this differs from the lesson. In a way.

 what is it?