I'm trying to upload a PDF for a paper of mine that is known to CiteSeer, but not known to Academic Search:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.47.7107&rep=rep1&type=pdf
However, the site replies "Please input a valid url". It looks for a ".pdf" extension, which is naive.
I was able to fool it into trying to download by adding "&bogus.pdf" at the end:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.47.7107&rep=rep1&type=pdf&bogus.pdf
Now it says "Sorry, the system failed to get the PDF file". I tried this URL and CiteSeer serves it just fine.
SO WHAT GIVES?