Strange sign-in problems

I've been having intermittent strage happenings with my Apple id on my iphone. It's a 5 running ios 6.1.2. Often, I will find it signed in (on the app store app) after a sync the previous night (most often I check it is signed out after the sync but not always). Odd thing is it doesn't show the balance on my account, just my user ID. Wore it won't let me sign out until I press "View Account info." At the same time if I happen to use the music app I'll get a pop-up box wen I open it with my id and the password box empty to accept my password. WTF??? I don't need to sing-in to listen to music do I? In fact no I don't as I usually hit cancel and it goes away. Still can't figure out the sign-in weirdness, more annyoying than anything, though it does get frustrating trying to tap the sign-out button with no response. Any idea what is going on?

Bump, anyone know what is going on? Just had it happen again.