I can only say i can run poweramp even in air plane mode now. I am on jb on my phone. N tat previously there was this issue reported on gingerbread. Sent from my GT-I9100 using Tapatalk 2

This licence issue with poweramp has been reported b4 in gingerbread as far as i rem. Has been fix in ics n above. Sent from my GT-I9100 using Tapatalk 2

You can try go to poweramp settings - > audio - > advanced tweaks - > check / uncheck direct volume control. Disclaimer: I dun own a dx100 but i guess no harm trying. Had a similar problem with poweramp when i use it with an audio mod on my phone. Sent from my GT-I9100 using Tapatalk 2