It sounds like you took your risks on an unknown product, discovered it didn't work the way you thought, and figured out a complete workaround solution. Is there still a problem?
this sounds stupid, but make sure both your grounds are connected to the arduino. The same thing happened to me when I got mine. Where did you get yours from? I too, went to alibaba... I'd be interested to know.
Also, if you post a picture of your pixels, I can confirm that they are/are not using the ws2801 chip!
I should point out that many of those driver chips that are listed in the FastSPI library will also have a different name. For example, the LPD1101 is the next generation for the LPD6803, so you can use the LPD6803 configuration in FastSPI to drive the string just the same. You can even drive a WS2803 (18 channels) with it using the WS2801 (3 channels) driver.