Thanks for the response itimpi, I think I need to spend a bit more time working with it. I installed it and downloaded a couple of news feeds and viewed them, nowt it will not view anything. I'll see what I've messed up and check the help and see if I can figure it out.
UPDATE - it seems hit or miss now sometimes the viewer will open sometimes not, so it is not any of the books I downloaded but the viewer itself. This problem isn't pertinent to this topic though so I'll start a new one if I need to.
FIXED - I figured out the issue with viewer, it is the same as described in
this thread