Hi javier,
In that case, you may have unpaid bills for one or more of the 3 other projects. You have two options, sign up for another Google account and deploy your new project under that account or set up a billing account on your existing account.
Welcome to the ODK forum, @javier! We're glad you're here. When you get a chance, please Introduce yourself here!. I'd also encourage you to add a real picture as your avatar because it helps build community!
Thanks,
Imran