how to associate private key with a certificate in keychain

I just downloaded iphone sdk 4. when I try to install on the device I get

"Code Sign error: The identity 'iPhone Developer' doesn't match any valid certificate/private key pair in the default keychain"

I have gone through the process of creating a provisioning profile and cert through iphone Development Provisioning Assistant. However, after installing the profile and cert the assistant asks to check whether public and private key are paired (surprisingly, it shows a pic of what seems to be a private key and cert being paired, i.e. the cert is 'under' private key in hierarchical terms. This is not the case in my k开发者_JAVA技巧eychain. Public key, private key and cert are there but there doesn't seem to be any associations.

Does anyone know how to pair a private key and certificate in keychain please this please?

ps. I have checked this thread but I'm hoping there's an easier way.

iPhone app signing: A valid signing identity matching this profile could not be found in your keychain

I wrote a wiki page (here) that describes how to export your certificate and private key pair. It's intended for my iOS development clients to send me their ad-hoc, but I believe it will solve your problem, too. The key is to make sure that you export the certificate and private-key PAIR all in one go -- not as two separate exports.

Hopefully, the screenshot near the bottom of that page will help out.