Is this you? You updated your iPhone to iOS 4 and now you’re looking to multitask — and it isn’t working? What’s going on? Here’s what you need to know. With iOS 4, multitasking is already here, but in order to use it developers must update their apps to support this new feature. (We have a short list of multitasking-enabled apps at the end of this report). First of all, a quick explanation of what multitasking is on an iPhone. The news here is that it isn’t really multitasking per se, more enabling access to specific tasks from within enabled apps. Because these tasks are tasks you want to…