I currently run a Netgear AV500 powerline networking system throughout my house. If I add an Insteon system will both systems coexist and function independently without interference? Thanks in advance for your assistance.

From Netgear's site. I don't know how I didn't find this before.

"Powerline technology can co-exist with phone line and RF networks with no known problems. Powerline products operate in a different frequency band than powerline control technologies such as X-10, Insteon, CEBus, UPB (Universal Powerline Bus), and Lonworks and will coexist with them in the same home."

Glad you got your answer.