Prius/Siri Problems

Has anyone ever been able to successfully make a call using Siri through the Prius' bluetooth system? From my experience, when Siri is connected to the car and I ask it to dial, it attempts briefly...and then immediately hangs up. I actually don't think it's a Siri problem - I think it's because Siri has to use the Prius' phone software simply to talk to the driver in the first place (thus when I'm using Siri, the Prius phone screen appears with "TALKING"). I've noticed before - even with other phones - that if that screen is already apparent it hangs up right away after attempting a new call. It's like there's some kind of hiccup or glitch when you try to do two calls back-to-back and you're connected to the Prius bluetooth. This would happen when I'd try to immediately redial a number on my old Blackberry. All that said, wondering if anyone found a fix for this beyond simply uploading your contacts into the Prius computer and always dialing directly from the car and foregoing Siri entirely? Is there any chance Toyota has a new software update as a fix for this? Thank you!