I've just downloaded V 5.2 and have been following the tutorials and I tried changing the text for a few templates: GoListHeader, SeeListHeader, PlacesObjectsLabel, and a couple others, and none of them are reflecting the change when I play the game.
I've attached my game file, please tell me what's wrong here.

This is a known bug: http://quest.codeplex.com/workitem/1078

The way that Quest handles templates (I think) is that it does the substitions as it loads in the code. If you look at the code for your game, it starts like this:

<!--Saved by Quest 5.2.4515.34846-->
<asl version="520">
  <include ref="English.aslx"/>
  <include ref="Core.aslx" />
  <template name="SeeListHeader">There's</template>
  <template name="GoListHeader"> Go to </template>
  <template name="UnrecognisedCommand">Unknown command.</template>
  <template name="YouAreIn"></template>
  <template name="PlacesObjectsLabel">Places / Objects</template>
  <game name="Test_1">

The first two lines are house-keeping, then we get to the important stuff. The third line loads in "English.aslx" with all its templates. The fourth line then loads the core functionality, and as it does so, all the template substitutions are made. Then, in the next few lines, you define your templates... but it is too late now, the things they should be substituting are already loaded.

The bug, then, is that by default Quest will put your templates into the code in the wrong place, and it is acually pretty easy to solve. Just move the fourth line, where Core.aslx is loaded, to after your templates, so now your game code should start like this:

<!--Saved by Quest 5.2.4515.34846-->
<asl version="520">
  <include ref="English.aslx"/>
  <template name="SeeListHeader">There's</template>
  <template name="GoListHeader"> Go to </template>
  <template name="UnrecognisedCommand">Unknown command.</template>
  <template name="YouAreIn"></template>
  <template name="PlacesObjectsLabel">Places / Objects</template>
  <include ref="Core.aslx" />
  <game name="Test_1">

Okay, thanks for your help.