Read the data sheet on the WS2801. It tells you when/where you need to add the resistors.
However, I have run the FastSPI testled sketch on a full 5m reel straight out of the box with no problems what so ever. The only change I made to the sketch was to add the proper dataRate line, which is missing from the sketch. No resistors added, just hook up the four wires, make sure the 4 wires at the end aren't touching anything metal, and turn it on. In fact, I just grabbed two reels, hooked them up in parallel to my Uno, using FastSPI. I only ran one sequence, which is the single color down the whole strip, because it's not hooked up to a high amp power supply:
(the freezing that you're seeing, if any, is just the way YouTube processed the video - the chase is smooth with no hiccups.)