I just bought the Razer Megalodons and I've run in to a problem. I cannot transmit while playing audio. I also keep getting "USB bandwidth exceeded" errors. I'm using a 850W power supply and I used to be able to transmit and receive audio simultaneously in the past using a USB headset.
I'm using Windows 7 64 bit for gaming, and my headphones are plugged into a USB 2.0 port.
I've discovered that I can transmit/receive if I plug my G15 keyboard into the USB hub that is part of my monitor, and keep the headphones plugged into the USB ports on the motherboard.