iPhone lock screen/multitasking bar audio controls don't work From time to time (in fact very often) my iPhone will stop displaying the lock screen "now playing" info, and subsequently the controls won't be there.

I can still start the music app playing something, but I can't pause or skip tracks.

The same thing can be seen if I try to use the multitasking audio controls (swipe "left" on the multitasking bar). The play/pause button won't stop audio playback. Can't skip.

Same problem with the headset remote buttons. Can often start audio playing (although what it'll play is random). Can not stop/pause, can not skip.

I've not been able to reproduce this reliably, but it happens often. The phone is in this state more than it isn't. A restart resolves this most times.

How to fix?
Possible Causes:  


Mobile substrate add ons on a jailbroken device  
Corrupt event handling events  
Loss of data with streaming services  
Accessory interference  
Airplay  
Older version of iTunes  


Several things to try:  


If you are jailbroken try booting into safe mode (SBSettings Feature).  
If problem is with data streaming app then try the iPod app.
If accessories are connected, disconnect them.
If the problem persists, restore to the latest version of iOS and update iTunes.