KirAsh4:
The only issues with length is that at some point you need to add some pull-downs to the data and clock lines at the END of the string, to avoid reflection of the signal.
Do you have any more info on this?
More specifically, I purchased a similar 5m led digital strip,WS2801IC 32pcs IC+32pcs 5050 SMD RGB/meter with a total of 160 (32*5) LEDs. I've paired this up with a duemillanove and a 5V 5A PS. On the arduino, I've ran the fastSPI test leds PDE and the adafruit WS2801 strand test PDE, with consistent errors after exceeding about 60 LEDs. The failure that occurs are the first led pixel being off color and some leds toward the end of the string or all leds begin to behave erratically. Any thoughts? Maybe throw in a pull down resistor after the 50th?