Question:

Why do some Intel Macintoshes fail to reconnect to the server after a temporary loss of network connectivity?

Answer:

A bug in the Macintosh OS X Finder prevents clients logging in with the Kerberos authentication mechanism from an Intel Macintosh from reconnecting to the server. Users that have temporary network connectivity issues will not automatically reconnect to the server, and instead will need to manually re-login to the server. All changed documents they had open at the time of the incident will be lost and the files may be corrupted.

This bug has been reported to Apple, but has not been addressed as of version 10.4.8.