There was a problem connecting to the server "my_server"

At one time, a long time ago, I had a mount for "my_server/Our_Pictures" set up. Now, whenever I try to do something like, say, change the background image on my desktop, I'm presented with a message saying "There was a problem connecting to the server "my_server"". I click the "Ok" button, the dialog goes away but about 30 seconds later it's back. And it keps coming back every time I dismiss it until I reboot the machine. I've looked around trying to find any reference to that mount but I can't find it anywhere. Not Go -> Connect to server -> Recent servers, not anywhere in the file system, not in my login items (again, it only happens when I try to navigate somewhere in finder when, say, setting a background image for example), nowhere.

Looking at the messages that show up in Console.app, I see :

9/16/12 6:28:51.418 PM NetAuthSysAgent[22600]: smb_mount: mount failed to my_server/Our_Pictures, syserr = No such file or directory

So basically, I have two questions :

1) How can I prevent this fromm happening in the future? Where is the reference to this server so that I can delete it

2) If 1) above is not possible for whatever reason, how can I make it so that it doesn't keep trying to connect?

thnx,

Christoph