If when you turn on your BTunes it goes into pairing mode, indicated by the LED blinking red and blue alternatively when you have already previously paired it with your bluetooth device it means that the BTunes was reset to forget previous pairings.
To solve this problem turn the BTunes off and then select the BTunes profile on your bluetooth device and select forget device. Next, turn the BTunes on again and have it enter into pairing mode. Pair the BTunes with your bluetooth device once again.
To prevent this from happening in the future make sure that when you are turning off the BTunes do not hold down the multi-function button for too long. Just hold it until the red LED flashes to indicate the unit has powered off, if held for around 5 seconds longer than that the unit will be reset and the LED will flash purple.