Btw, only third party apps count towards the 15, but that includes apps with live tiles and those that only provide push notifications. And apps like Flixter and eBay will register to your push channel even if you only open them once and never look at the again. Plus, if your registry key balance is already out of whack (ManagedEndpoints vs. Endpoints) deleting these apps will not remover the required left over registry keys. Flixter is one of very few apps that will actually remove the offending key if you disable the live tile feature.
You also don't need 15 push/live tile apps to have a problem. As some apps will disconnect/reconnect after a soft reset for example, a single app can be responsible for 3, 4 or more left over registry keys. Some apps may be worse then others at this, but of the 20 I have tested, they all do it. To be clear though, if Microsoft implemented the fix described in my previous post, apps disconnecting/reconnecting would not(theoretically) be a problem. Disconnmecting/reconnecting is still an issue that needs attention, but it would not shut down all your tiles. You would only need to open the app to wake the tile up again.
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