I’m running Xcode 4.3.2, under Lion 10.7.3, but every time I’m installing my iPhone app on the device it keeps asking me for an Admin user name and password.
I’ve done everything suggested here, and even have reinstalled Xcode:
Another StackOverflow related question
But without success so far.
Here is a picture of the window that is appearing all the time:

Any other suggestions on how to solve this problem?
The problem was that my Developer Certificate on Keychain was under “System“, on the left hand panel, which is always locked, requiring my password to unlock!
Then I moved the Developer Certificate to “login“, which is always unlocked, and now everything works perfectly. The annoyance of xCode asking for the password is gone.
Please see this picture for more details: