i had the same issue, and now i cant even get my phone to bluetooth with it anymore. seems the receiver is stuck in being visible only to the device it was connected with (my phone) and since ive removed the pairing from my phone to re-connect it, it won't show up again and now i cant use it with any device.
when it was working, i did have that issue as well though, with the sporadic quality. unbelievable. this fucking thing costs 900 dollars, it shouldn't have a problem playing or pairing with any bluetooth device.
I had a similar issue. This is how I solved the problem.
Husband paired his phone with the Marantz 5010 and it worked fine. Two weeks later he decided to unpair/remove the phone from the Marantz and the Marantz froze. I still had cable, Blue-ray, and video game players working but I do a lot of listening to online radio and internet radio. Every time I tried to bring up those radio features the Marantz kept saying "No Connection" and that it was "trying to connect to the last paired bluetooth device". I looked at the manual. No good. Made certain my SO had disconnected his phone, he had. Looked on the net and found this thread. Decided I'd sleep on it.
I'm an engineer and I've always felt a hard reboot can solve a lot of these types of electronic freeze problems. Turned on only the Marantz and hit the off button on the power strip. Went out to make myself a cup of coffee and finished the last few pages of my current book. About 90 minutes later, fired up the Marantz and up popped a lovely invitation to update the firmware. Why not. Thirty minutes later, update completed and every thing had rebooted and was back to full functions. We later went out to dinner and when we got home we turned the Marantz on again and all is fine.
I know our problem was trying not to keep a paired phone connected while most here are trying to get and keep a phone paired, my thinking is perhaps a hard reboot and then updating the firmware might work for y'all as well. HTH
Cheers, Sarah