Error using native iOS mobile SDK:

After entering credentials and approving access in the web view, I get the following error in the iPhone simulator:

"*** WebKit discarded an uncaught exception in the webView:decidePolicyForNavigationAction:request:frame:decisionListener: delegate: <NSInvalidArgumentException> -[UIDevice macaddress]: unrecognized selector sent to instance 0x6e521f0"

The screen is then blank. I can see in the SFDC web UI that the app was authorized, but - oauthCoordinatorDidAuthenticate:coordinator is never called...

Any idea what's going on here?

Thanks