can only see posts from one author?

I’ve recently (thismorning) installed WordPress 1.0.1 at http://jael.bluewire.net.nz. However, I can only see posts from one author at a time on the front page or catergory listing. As soon as I post, my posts reappear and my friend’s dissappear, and vice versa. All the posts show up in the Edit control panel tab. The three posts can be accessed directly via:
http://jael.bluewire.net.nz/archives/2004-01-27/argh/ (mine)
http://jael.bluewire.net.nz/archives/2004-01-27/welcome/ (dave’s)
http://jael.bluewire.net.nz/archives/2004-01-27/of-mistakes-and-nukes/ (mine)
But of course, if you look at the main page, you will see mine OR dave’s posts. Not both. I’ve fiddled around in the control panel for a while now, and I can’t figure out the solution. Anyone got any ideas?