Phone call drops cable modem connection

Hello,
How do I fix this? Everytime my cordless phone rings my (hard wired) ethernet connection between the cable (not DSL) modem and my wireless router drops. Every machine on the wireless router can still talk to each other but the internet connectivity is gone until I reboot the cable modem and wireless router. I changed phones it still happens. I changed cable modems it still happens (I also changed the wireless router - still happens!)