Mac author and MacFixIt reader Kirk McElhearn reports a problem with Panther where accumulated network mounts -- for servers and computers that are no longer actually connected -- can cause slowdowns or even freezes:
"Several of my applications were hanging. I got the spinning beachball, and had to force quit them. But it took several force quits to kill the applications, either from the Dock or from the Force Quit Application window (Command-Option-Escape).
"One thing I noticed was that the hanging occurred in operations which should have displayed an Open or Save dialog. The solution came when I recalled a similar problem with OS 9 hanging because of aliases to recent servers in the System Folder's Recent Servers folder. So I fired up the Terminal and went to /var/automount/Network, and, indeed, found a half-dozen directories there that corresponded to different servers. After deleting these, everything worked fine.
"If an application hangs when it's about to display an Open or Save dialog, it could be that the Finder is looking for those recent servers before displaying the dialog..."