单击向上按钮后返回活动时ListView消失

I'm using Parse.com to populate a ListView in the second activity of my app. Clicking on an item in the ListView opens up a third activity. The problem is that when using the Up button to return to the second activity the ListView is gone. For some reason this behavior does not occur when the Back button is used. Also, it does not occur when just using a normal query in the 2nd activity. Something about the query.whereEqualsTo("department", department) line is throwing the whole thing off.I'm using Parse.com to populate a ListView in t