The point being that if you think, as I did, that you only need one, original backup of your wallet, it's not so! You're constantly using up that 100 addresses, and if you don't re-save your wallet.dat file after the next 100 addresses are created and used, and something happens, all the newer transactions can be lost to you!
So maintaining your wallet backups is extremely important. You need to guesstimate how often you need to backup, or simply backup often. You can do it with the wallet backup function on the main menu, I forget which drop-down item, 'cause I don't have my wallet on this machine to look at, but from there, you can name the file, something like DarkCoin_2-26-14.dat and save it anywhere you like from that menu. No need to close the wallet even.
Can someone confirm or challenge this above, please? I don't think is true, but I'm not sure. Thanks!
you only need to backup your wallet once, the addresses being talk about are the recieving addresses, your wallet private key, is only 1 key, the rest is calculated from that key
I use Electrum for Bitcoin, it's a far superior client IMO shows you exactly what it's doing too.