I hit this before already from time to time on various CiteSeerX pages, and I think it doesn't always occur - when I tried to reload the page, the problem also disappeared. Just now, it does not disappear on pressing F5 or hitting Enter in the location bar again, so maybe there's a chance you can reproduce it too.

Steps to (maybe) reproduce:
1. Go to http://citeseerx.ist.psu.edu/viewdoc/summary;jsessionid=B2E72BD7BE16ED2D9041C628354D1EC3?doi=10.1.1.16.700
2. On the rather top right-hand side, note the "DOWNLOAD: PDF" text, where "PDF" is a link. Although being displayed correctly, the link does not transform the mouse arrow into the "hand" cursor, and does not show the standard link options (including "Save link as...", which is unfortunate as I have to open the HTML source in that case).

On other CiteSeerX pages, the same "PDF" link worked flawlessly, maybe it will also work on the mentioned page when you try to reproduce it. Browsing through countless papers makes it show up sometimes, though. I would guess that their CSS is sloppy too (the same site also had problems with showing the search field before - that works again now), but maybe the issue is not solely in their responsibility.

Please try and see if you can reproduce that bug. Thanks!