Ive opend a ticket with the same issue 8/10-2013
The fix for this prob,is turn of all the apps,turn of the phone,when it reboots connect the headphones...didnt work for me
on any iphone 4,but thats line 6 solution to this problem.
This is a letter sent to me 29/10.../Thomas
Hey Thomas, So far we only have 2 cases of this symptom being reported, and the other customer has reported that doing it in this order has resolved the issue for them. We apologize for the downtime and inconvenience your experiencing with your Mobile In. Our software team is still investigating this issue and will work towards a fix in a future update. Your welcome and if you have any future questions feel free to respond to this ticket. -Don Customer Support Line 6