Xcode 4.3.2, issue with running on simulator

I have found by chance, it is not a solution by any means -

When xcode hangs, saying it is running the app, but nothing is on simulator, opening the simulator from the dock by clicking on the dock icon (not using command+tab) seems to work.

It is very weird,but it works; atelast till xcode fixes it.

Besides a restart, there is one other way I've managed to get around this:

Let's say your app hangs, go to the targets selector in the top of the Xcode window and change your sim target to a new SDK (or if you don't have another SDK, change it to a universal app and run on the opposite device simulator).

Then, when your app loads on the new device/OS completely, quit the sim, change your targets back, et voilà!

I had the same damn issue on XCode 4.5.1, but I resolved it just now. When the program is running, it gets compiled but doesn't show anything on the simulator. just click on iOS Simulator icon in dock in order to bring it to front. Click iOS Simulator on top left -> Reset content and settings -> then force quit the iOS Simulator and run the program again. !!