When i first got my DI - i could silence all the sounds for emails etc. but when calls came through it rang. Now everything is silent and i am missing calls. Am I missing some setting?
Regardless of whether the device is capable or not there are profiles apps that would allow you to create profiles such as "phone only". Don't assume that you have to use your device as it is delivered out of the box. The extensibility and versatility of Android is really one of its biggest strengths IMO.