Hi,

are you sure that the IR unit that is placed into your key is originally for a V8. The Problem you describe seems to be a Problem of the IR unit in your key. A few months ago I bought a key with a working IR unit for my V8. The key originally was a key for a 95 Audi A6. When I tried to register the key at my car the same things you have described happened to me. I also have another IR key for my V8 and this key works fine.

Best regards
Martin

Life sucks and then you die.