iPhone simulator doesn't respond

[admin]

Whenever I try to run my app the iPhone simulator pops up and the xcode debugs fine but nothing happens on the iPhone simulator. Even simple apps don't work.

Root of the problem possibly?: I downloaded the SDK on a macbook then moved the Developer folder onto an external drive. (I want to work on a different mac.) *Note: The simulator works on the mac I originally downloaded the SDK on. My knowledge about developing on two macs is kind of vague but I know you have to get private keys and certificates and such. Does this apply for simulator development? (I'm not in Apple's developing program so I can't develop on a real iPhone/Touch.) So moving on, I can move my external drive onto the new mac and run all the applications fine EXCEPT for the iPhone simulator. Even just running the iPhone simulator freezes without showing anything.

So just for clarification: The iPhone simulator on a mac using an external hardrive as its source for the SDK freezes, however, the original mac's simulator that downloaded the SDK works. Why does the iPhone simulator freeze?