No, the carrier has nothing to do with it. Some A2DP Bluetooth headsets will play text alerts even if A2DP is turned on, others won't. The Jawbone ICON will, the Jawbone ERA won't. However, if you disable A2DP on the ERA, voice dialing will no longer work. It will route the call, but you won't hear any audio through the device, even after toggling audio sources. For this reason, you are forced to leave A2DP turned on, but you won't hear any audio alerts. Pretty crappy for a $130 Bluetooth headset. It's a nice headset with killer battery life, but the A2DP problems that are associated with it make it no worth upgrading to. I've tested it with two different ERAs and experienced the same problems on both of them.