iTunes won't shut down

[learninmypc]

Twice today I had my usb iPhone/iPad recharger plugged into my computer (I had forgotten to unplug it from pc) so when I plugged my iPad in to update the ios, itunes popped up. I unplugged the usb from the pc & plugged it into the ext cord not connected to pc but iTunes kept popping up. I x'd out but it would pop back up again & again so the only thing I thought of doing was to reboot, I did & thankfully it stopped. It happened later too. Anybody know why?
I know when the iPad/iPhone is plugged in,it will pop up,but why continue after its unplugged?
Not that it matters, but I know the iPad don't recharge plugged into the pc,just into the ext cord . TIA

 

[DelJo63]

I believe it's all about Sync & Updates. Once launched iTunes will stay active regardless of the attachments.

 

[learninmypc]

There was just an update for itunes so I'm going to see if it happens again. It just seems weird it continued to happed when the iPad was not connected to the pc. Thank you

 

[learninmypc]

Evidently the update fixed it, it didn't happen again. Thanks for your help @jobeard