HAVs now have a new contract address
As part of the launch of nUSD, we are also making a change to the Havven smart contract that may affect your experience on such platforms as MyEtherWallet and EtherScan. This is due to a new proxy contract system that we implemented to be able to update the contracts remotely without affecting user experience. We have contacted each of those platforms and the issue should be resolved soon.
Update: As of December 2018, as part of our rebrand, HAV is now called SNX.