A few months ago I was trying to help a new SatPC32 user track the ISS. His prediction was way off because of a recent boost in the ISS orbit. He was getting bad predictions using elements from AMSAT and Spacetrack. I figured that NASA must surely be the most authoritative source of the ISS orbit. I stumbled onto a NASA web page that supplies details of each boost and DAILY predicted ISS 2-line elements after the boost.
http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/...
The date is in epoch format, so you have to convert it to today's calendar date. Today is 2014 day 239, which in epoch format is described at 14239. Here's a link to an epoch converter:
http://www.epochconverter.com/epoch/daynumbers.php
It's kind of a nuisance to convert the date and manually copy today's predicted 2-line elements into your Keps file before attempting to hear the ISS. But it works!
Wayne Estes W9AE Oakland, Oregon, USA, CN83ik