Problem running iPhone application on iPhone from Xcode (and in Instruments)
This happened to me as well (more than once). I ultimately had to restart Xcode to resolve the problem (after verifying the code signing settings were correct, the provisioning profile was installed, etc..).
I had the same problem and restarting Xcode solved it. Of course I checked that the right provisioning profile was installed on the iPhone and that the bundle id in the project settings matched the provisioning profile.
It says it couldn't install the profile. Check thoroughly your code sign settings and verify after you build the application that the profile you used for code signing indeed the one you chose: go inside the package of the built application, find the embedded.mobileprovision file, open it with a TextEdit application, look for <name> tag and see the value. If the value doesn't match the profile you have set in your project, that's might be the reason for the problem.