I recently built a new box using an Intel i3-550 processor and MSI MB. It replaced a Dell Pentium-D machine (which I still use). I've been trying to share my Public directory using gnome-user-share, which has always worked perfectly in the past. In fact, I can see the Public directory on the Dell without any problm from the new machine, but when I try to access the new machine from the Dell, I get the following error:

Unable to mount location

DBus error org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

The only difference I notice so far is that the kernel for the new processor uses -pae.