[Zope] socket missing?

[Richard Lanham]

ZopeList:
I am running this:
Zope 2.3.3 (binary release, python 1.5.2, linux2-x86) 
Python 1.5.2 (#10, Dec 6 1999, 12:16:27) [GCC 2.7.2.3] 
On RedHat 7.1

Everything is stable for many months until yesterday: I get this 
traceback on start.

Traceback (innermost last):
  File /home/rlanham/zope23/z2.py, line 623, in ?
  File /home/rlanham/zope23/ZServer/HTTPServer.py, line 391, in __init__
  File /home/rlanham/zope23/ZServer/medusa/http_server.py, line 550, in 
__init__error: host not found

So I comment line 550 of http_server.py:
ip = socket.gethostbyname (socket.gethostname())

and hard code my ip:
ip = "xxx.254.xx..xx"

Zope starts up now, that's good, but can anyone tell me what happened here?

TIA,
Richard