Go look up the NASA site that was linked and find the supposed trajectory of the ISS. Align your telescope properly and try to find the ISS where they say it should be, document your findings (write positions you point your telescope at down and such), take pictures, and post up your findings here. I am curious to see the result.
I would try this, but I don't have a telescope, can't really afford one and if I did find one post pictures with it, you'd claim they were faked. This is the only way to find out!
(Note, documenting it in high detail is very necessary, or we would just be able to claim that you weren't looking the right place!)