What about my first novel?

I sold my first novel to a publisher on my own - no agent. I'm hoping to obtain an agent for my second. Here's my question. What happens with my first book? Should the agent find a publisher for my second novel, does the new publisher ever try to obtain rights to the first novel? If so, how does the agent fit into this? Thanks.
Linnea

victoriastrauss said:

It's the opposite. The old publisher will often claim option rights on the second book. Check your contract.

- Victoria

Click to expand...

Really? Shoot, I hope not! Gotta check that out. Thanks.
Linnea

Just checked. The related clause says 'The Author further agrees to inform the Publisher of any contracts for forthcoming books the Author may have with other publishers for works in any genre.' There isn't anything about claiming option rights, just a requirement to notify. So why would they want to know?
Linnea