Why is my Mac constantly trying to connect to another server?

After logging on, I see this dialog box pop up. Whenever I dismiss it, it reappears 30 seconds later. (Stealing focus at the same time! Grrrr!)

"Slate" is my old iMac, which is sitting on the desk next to me, turned off. How can I stop my new Mac from constantly trying to connect to my old one? Both are running 10.7.1.

Check System Preferences>Accounts>Login Items to see if there is a disk that is supposed to mount when you login. Make sure you check all of the user accounts.

I'm pretty sure this was happening because when I logged out, I was running an app which was located on the other computer.

I logged off and unchecked the "Reopen windows when logging back in" box, which stopped Lion from trying to reopen the app the next time I logged in.

I suspect you are connecting to a legacy file server as described in the kbase article below.

http://support.apple.com/kb/HT4700

We saw similar pop ups but clearing up our mounts addressed the issue.