If you have PPT Viewer installed on the Screens then you shouldn't have the mouse pointer showing - I, too will be surprised if you do. However, if you have installed the full version of PPT application on the client, then you WILL get the mouse pointer showing. To eliminate that you can use the nomousy utility and that will take the mouse off.
Here is the link to download the utility:
http://www.mediafire.com/?vziibbqddk6bu
Bill