ASA online activation

I activate ASA successful at home (wirless network).

But when I start ASA at company (Broadband network), it shows "need activation", click OK button,then says "Online activation successful".

However, When I play ASA at home again, the same problem appears.

I'd like to know if ASA can't change the way of access to the Internet? (I mean that ASA online mode must be consistent with its first activation network environment.)

(or how many times can I re-active ASA in different network environment? )