I have the cable shown on http://www.ebay.com.au/itm/331313899587?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT, connected to a 5W adapter on one end and a USB male to USB male keystone coupler on the other end. From the other end of the coupler is a 20cm USB to micro usb cable plugged into the Pi. With this setup (once I turn on the power) I get the multicoloured screen for a second, followed by the initial command line bootup sequence, then the Pi reboots. The Pi works fine when using the 5W adapter with a 1.5m USB to microUSB cable plugged directly into the Pi. The Pi also works with the 20cm USB to microUSB cable. Could my issue be caused by the 1.5m USB to USB cable or the fact that there is a USB keystone coupler being used?
Well from my experience I noticed power drops if adapters/couplers are used. It’s the thickness of the cable as well. The one you bought is 24/28AWG. Maybe try thicker cables (i think usb standard cables can go as thick as 20AWG) or try soldering what you have to eliminate the coupler. No guarantees..
In my snes/sfc enclosure setup I had to use thick cables cut from a pc psu because the normal microusb wires would give me that colored square.