I think I have been looking at this the wrong way.
For some reason, possibly after loading latest updates, I feel the trouble comes from wrong configuration in IE7. If I open IE, it immediately launches Aol for me. I minimise Aol and type in the name of the website. This opens and offers the same links as on Aol alone. But this time the PDFs will open and are readable!!
Surely this exonerates Adobe and AOL?
Can someone please tell me what changes I must make to make Acrobat display a file, rather than spirit it away in the Aol environment.
Try disabling the "View In Browser" or "Web Browser Integration" feature in your Adobe Acrobat viewer (for plug-in and standard version). Doing this will force your Acrobat viewer to display PDF outside your browser in a separate window. In most cases this will fix your problem. Shown below is how to disable "Web Browser Integration"