How to fix error "pa_context_connect() failed: Connection refused" with bluetooth?

On Ubuntu 14.04 I have sometimes problems to connect to a bluetooth device (audio sink). Sometime it works, sometimes it does not work.

I have followed the solution given here and looked at this suggestion, but still I have the problem sometimes. I want to be able to use the bluetooth device as audio sink without rebooting my device!

I get the following errors:

> sudo pactl load-module module-bluetooth-discover
Failure: Module initialization failed

I still have made the changes as suggested for the first solution.

Additional information:

• I have two bluetooth icons in my Status menu. Maybe there are competing apps/services/tools installed?
• When trying to connect to the audio sink using the Bluetooth Manager I get the message Connection Failed: Stream setup failed.

pactl load-module module-bluetooth-discover