The seed used for generating the extended BIP32 key for each wallet is generated as so:

1. The user master key is hashed with the password using HMACsha256 twice. (byte 1 through 32 is used for the seed. Byte 0 is the Djswallet version byte and byte 33-36 is the password checksum. There is also the base58 checksum in there)
2. That data is then concatenated with the network name
3. That data is then used for the seed for the BIP32 key.

Each network will have different keys.

The Djswallet version byte will allow me to change the key format in the future and still work with current keys

Note: Don't use namecoin operations yet. The only thing that works is NEW NAME. FIRST UPDATE and UPDATE NAME are not working yet. The site is also still ugly.

Thanks for trying it out.

I think this will be the first web wallet with full Namecoin support.