This is the backtrace we get when applying the changes in redhat-config-network
on RHEL AS 2.1.

Traceback (innermost last):
  File "/usr/sbin/neat", line 1210, in ?
    gtk.mainloop()
  File "/usr/lib/python1.5/site-packages/gtk.py", line 2608, in mainloop
    _gtk.gtk_main()
  File "/usr/lib/python1.5/site-packages/libglade.py", line 28, in __call__
    ret = apply(self.func, a)
  File "/usr/sbin/neat", line 392, in on_applyButton_clicked
    self.save()
  File "/usr/sbin/neat", line 271, in save
    self.saveHardware()
  File "/usr/sbin/neat", line 283, in saveHardware
    hardwarelist.save()
  File "/usr/sbin/../share/redhat-config-
network/netconfpkg/NCHardwareList.py", line 276, in save
    modules.write()
  File "/usr/sbin/../share/redhat-config-network/netconfpkg/Conf.py", line 
981, in write
    self[key] = self.vars[key]
  File "/usr/sbin/../share/redhat-config-network/netconfpkg/Conf.py", line 
936, in __setitem__
    replace = key + ' ' + varname + ' ' + endofline
TypeError: illegal argument type for built-in operation

Local variables in innermost frame:
endofline: None
value: {'alias': None}
self: 
varname: eth1
missing: 1
key: alias
place: 0
findexp: [	 ]*alias[	 ]+eth1[	 ]+