What happens when an attacker completely controlls your Internet connection?
Yes, the scenario is possible. The attacker has two possibilities: censoring data sent to the network (likely your transactions) and censoring what the nodes sees from the network.

In the first case the isolated node will attempt to resend transactions that belong to it until they get invalidated or committed into the blockchain.

In the second case the isolated node will not receive incoming transactions and eventually will not receive blocks (if these contain censored transactions). It is however not possible to fool the node into considering transactions as confirmed without the attacker also producing a valid proof-of-work.

The same argument is valid for Satoshi Proof and Namecoin, you can hide transactions, facts and domains, but you cannot inject wrong information.

Once reconnected the node will synchronize with the network (download blockchain &amp; send its transactions) and eventually be up to date.