This is one of those things that’s not a big deal today but could be soon. Apparently there’s a limit on the number of live tiles you can have (like weather apps that update the temp or Twitter apps that tell you how many unread Tweets you have). And if you exceed it you simply get an error message to the app that’s generic so you don’t know that’s the problem. Further, there’s no central place for a user to track the live tiles they have active and toggle them. Sort of an odd limitation considering that live tiles use very little data (since it should be a small push of a speck of data to update them). Anyway, hopefully by the time there are 15 apps that use live tiles MS will have removed this cap.