NameError on "buffer"?

[Bill Janssen]

With Python 1.5.2, when I import a module, I sometimes get a NameError
on "buffer", which is a new, and apparently undocumented built-in
function.  Why would that happen?  Is the compiler perhaps not updated? 
Here's an example stack trace:

  File "<string>", line 1, in ?
  File "multlangimpl.py", line 25, in ?
    import multlang, multlang__skel, ilu, sys
  File "multlang.py", line 13, in ?
    import iluRt ; _imported_modules['iluRt'] = iluRt;
_imported_modules['ilu'] = iluRt;
  File "/var/tmp/usr/tmp/@12642.1/src/runtime/python/iluRt.py", line 409, in ?
    import traceback
  File "/import/python-1.5.2/lib/python1.5/traceback.py", line 6, in ?
    import types
  File "/import/python-1.5.2/lib/python1.5/types.py", line 18, in ?
    BufferType = type(buffer(''))
NameError: buffer

Bill