hyperlinks work once, then they do not a second time

Hello:

I have a presentation that has a few problems. I have a menu that has
several items listed. Each item when you click on it opens a PDF file. Here
are my problems, which I have no clue how to fix, although I have spent the
good part of two days trying to figure it out.

#1: Some of the pdf files open in adobe in front of the powerpoint screen.
This is what I want. When I close out Adobe, and go to anther pdf link, it
will open BEHIND the powerpoint screen. Is there a setting that I am missing
that will open any PDF's in front of the powerpoint presentation all the
time? It is annoying.

#2. After I open up a pdf link, read it, close out Adobe, and go back to
the presentation menu, that link no longer works. If I do click on it, it
goes to a black screen that says "end of slide show". How can I keep these
links active all the time so when a person clicks on them once, they can go
back and click on them again without having to relead the entire powerpoint
presentation viewer and presentation again?

I am using Microsoft 2003 by the way.

Any help would be appreciated.

JT