Invalid signature when uploading iphone app

Question

Im getting the following error:

Application failed codesign verification. The signature was invalid, or not it was not signed with an Apple submission certificate.

I uploaded this same app a month ago and it was rejected by the appstore. I fixed my errors and now I'm trying to re-upload it but its failing. I'm using the same certificate that worked the first time. I'm doing it the same way that worked the first time..

Can any one help?