Using LightSnake Into Garageband

I just bought a new guitar and I'm using a LightSnake quarter inch to USB cable to go into garageband. First, I am experiencing extreme latency (delay) from this thing. my output are my headphones and even when I use just my macbook speakers as monitors I get delay. Secondly, I get this horrible hissing sound from the cable when I am not playing it. I thought it would be the guitar but it's not, I unplug it and still get that sound and when I turn it all the way down I get the same hissing sound. Thirdly, the light on the lightsnake will not stop blinking. It is probably the most annoying part of this. Please help!