Why are my particles getting cut off the top and bottom of my render? I'm completely new to Blender, so probably all my wording is wrong :-) I started exploring it to be able to create a Youtube intro for my son, who wants to be a millionaire Minecraft Youtuber. So bear with me :)

I found an intro template for blender, you can take it off my Google Drive. This is actually where it gets synchronized whenever I save it locally:

https://drive.google.com/file/d/0B9par3l2T-UJQ1paY0tZRXlpN0E/view?usp=sharing

I'm rendering into PNG. The problem is that the particle cloud seems to fully extend to the right and left borders, but it ends abruptly towards the top and bottom:



Can you advise how I can have the particle cloud fully extend to all four borders?
Following my comment, considering the context (new to Blender, etc.), here is some more information.

The rendered scene parts (text and particles) are reworked using the 'compositor'. This compositor allows to tune how all this is mixed.

Here, it uses a box mask which is too small in its height (0.35).

To fix this, open another view. Set it to 'nodes editor' (1), then select the compositor (2), find the box mask and change its height (3).