Microsoft Project displays the project summary task name of the inserted project.
Though, you have renamed the file from Test1 to Test2, the project summary task is, by default, set to initial name given to the file — that is Test1. So, you have this issue.
To solve this issue,
a) — Project 2007 or Project 2003 – open Test2 and click Tools, Options, View tab and check "Show Project Summary task", — Project 2010 – open Test2, and click Format ribbon, check Project Summary task in Show/Hide section.
b) Double click the project summary task (row 0) and change the name from Test1 to Test2 and save the file.