How can I get the same Apple ID working with iPad, Mac mini and iMac?

[iMore Question]

I've tried to change my ID twice last week. I got the 'approval' mail from Apple after each new ID, but iCloud, iTunes etc in all my devices ask the old ID. And now they do not accept the passwords, not the new nor the old one. What is the solution?

 

[zerog46]

You went here: https://appleid.apple.com/

And you were definitely able to change your ID and can you log into that site with it?