Company DOT physical

Yes, the newest physical supercedes the older one.
Some companies don't require a new physical as long as your current card has a few months left on it.

 

You have to register it your self, they do not do it, they do cancel your old one.

 

Yes. If your concerned about something, then go with a company that doesn't require a new physical.

 

It is not called ability, it is called requirement, from what the doc told me.

 

This makes me wonder then.. what if the Older physical still has plenty of time on it but you failed a physical after getting the original one.

 

The failed one is what you now have, that is one of the reasons they are required to cancel the old one, even if it is just a week old.