Not sure if I should be piggy-backing this post, but I am experiencing a similar problem.
The problem I am having is that not all of the LEDs seem to be working and some of the chips between the segments get exceptionally hot. There don't appear to be any specific chips or LEDs acting up as it varies from power up to power up. The only thing that seems to be consistent is the first 12 or so LEDs are responsive - initially they just randomly flashed and changed colour, but this morning the LEDs were chasing colours when using the sample code. The second from last segment usually stays on with each LED set to some random colour. Sometimes the LEDs in the middle turn on, but they usually just stay white and not all LEDs would work. Occasionally some will flicker on and then off again.
I followed the tutorial on setting this up with an Arduino. I had to solder leads onto the input side of the strip. I triple checked the wiring, made sure the sample code was set to the correct number of LEDs, applied pressure to the chips all along the strip, switched the Arduino to the same power source as the strip, checked for any shorts or damaged connections (I didn't see any), but still the same problems. I am currently powering everything off of an ATX power supply and my probing reports a steady 5.15V. I have also removed my breadboard from the setup as the last post suggests and my connections, including the data line, are under 1 foot in length.
Thanks in advance.