Distribution Provisioning Profile valid signing identity

Having a lot of trouble trying to build an app for release, I have deleted everything from keychain ie wwdca, developer and distribution keys and certificates revoked all the certifictes from the portal, deleted the device开发者_JAVA技巧 from the portal, made a new app id, deleted the device from xcode organiser and started again. I have done this a couple of times and just cannot get past the valid signing identity for the distribution profile. Everything looks ok in keychain login, the keys are paired with the certs and they are all green ticked. One problem may be that in keychain> system >certificates the Software Signing certificate has a red cross and states it was signed by an unknown authority and there are no keys in keychain> system> keys. How would I renew the software certificate, would that even be the problem? Help Please