Problem while creating new altcoin, error loading blkindex.dat

Hi, I'm creating a new altcoin just to learn how it works. It's not going to be public, just used between some friends for fun. I know the world doesn't need another new coin. Anyway, I mined my genesis blocks (for both main and test nets) and then changed the nonce values and recompiled. After that, all that happens when I try to run the daemon is that I get "Error loading blkindex.dat". Was I not supposed to change the nonce? I'm a bit confused as to what's going on. None of the tutotials really explain these things, they just tell you what to do and leave you to figure out the rest.

Can anybody explain what I'm doing wrong? Also, how do I get the client wallets to automatically connect to the correct seed nodes? One more question, will new nodes in the future simply download the genesis block from the original node?

Note: I started with the mooncoin sources.

Thanks!!