I used to be able to run my application on my iPhone that was running 3.0. After I updated to 3.0.1 I get the error:
No Provisioned iPhone OS Device is Connected.
I followed Apple's guide in the terminal:
ln -s /Developer/Platforms/iPhoneOS.platform/DeviceSupport/3.0\ \(7A341\) /
Developer/Platforms/iPhoneOS.platform/DeviceSupport/3.0.1
but that didn't help.