Nothing shows, theme disappears when istalled?

I ran in to some problems while installing.

I transfered all WP 2.3 files to my server, managed to install it pretty okay, but nothing shows. I have a one theme there that works nice locally on Mamp.

I can log in to the Dashboard, but it doesn’t show any of my posts or theme or anything.

The same server already has one WP running, in a different database.

What could be the problem?

Help appreciated, thanks.