I am having exactly this same problem, and ironically, it also started right around the 10th. If I unplug it, I can make calls (with the poor reception that made me get one in the first place), but when it's running, I get the three beeps indicating that the call is connected and silence after that on multiple headsets. I've tried running directly from my modem, through my router and through a switch, nothing makes a difference. Since I can't actually call Sprint to troubleshoot this if it's plugged in, I'd love some online help.
I'll make this real easy for you. GET RID OF THE AIRRAVE. I got it, and it screwed up my phone to the point I thought I needed to change it out. It would not send some of my text messages and I would receive Texts in multiples of no less than 5. Phone calls would go straight to voicemail. All of the issues stemmed back to the airrave. Couple that on top of the nationwide network their having due to their "upgrades" and you've got an uphill battle on communication.