Whenever I'm reading a post for help, and I see those words, "advanced task killer," I know I'm going to have one more obstacle in efforts to remedy the issue(s) at hand.
There are experienced users on both sides of that opinion, mine being that ATK is a bit like having a nice, popular friend over for the weekend to do some chores for you and then discovering on Monday morning that somebody has siphoned gas from your car down to near empty.
Those things just don't always play nice with apps/widgets, and most often with dynamic ones such as you're having trouble with, and with syncing apps with which the task killers will cause resource draining sync loops, etc.
If it were my device (and I've been through this), I'd first nuke ATK forever.
Then I'd reboot my device and start some cleaning chores manually, most importantly backing up what I want to keep and then going into music apps via application manager and clearing data and cache (and defaults if not greyed out); all music apps.
Then reboot again and see how things are running.
One thing to always keep in mind is that the more syncing going on in your device, the more opportunities for issues.. manually syncing removes those problems, but most users understandably don't want to do that, so auto sync is used and things such as Facebook, email and weather, etc, will sometimes cause problems.