Reset Public Folder and File Sharing – Does not connect

Today I have set up a new MacPro at work. using the FIle Transfer, I cloned my old machine.
Going through the File Sharing settings, I by mistake deleted the Share on my Public folder. Reselecting the public folder to be shared again, it's lost its short name and now appears as a longer name folder. But it cannot be accessed anymore from other machines. My Mac appears on the side bar of other Machines in the office (mix of Leopard and Snow Leopard) as visible but hitting connect, results in nothing, and a 'could not connect message).
I tried turning file sharing on and off a few times, or just selecting the public folder and setting the share through the Info box. I also tried sharing another external volume through file sharing, but that also does not appear for other Macs in the office.

Any ideas?

thank you,

Stefan.