I'm having apparently the same issue when attempting to build an RPM (based on EPEL 2.6.5 SPEC) on CentOS 5.5 i386.

A straight configure/make/make install will work fine, but when editing Modules/Setup.dist to enabled *shared* (and then uncommenting the modules that I want to enable), and passing  --enable-shared to configure, I now get the following error during make-install phase:

PYTHONPATH=/var/tmp/python27-2.7.1-1.wt_el5-root-hans//usr/lib/python2.7  LD_LIBRARY_PATH=/home/hans/rpm/python27/Python-2.7.1: \
                ./python -Wi -tt /var/tmp/python27-2.7.1-1.wt_el5-root-hans//usr/lib/python2.7/compileall.py \
                -d /usr/lib/python2.7 -f \
                -x 'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
                /var/tmp/python27-2.7.1-1.wt_el5-root-hans//usr/lib/python2.7
Traceback (most recent call last):
  File "/var/tmp/python27-2.7.1-1.wt_el5-root-hans//usr/lib/python2.7/compileall.py", line 17, in <module>
    import struct
  File "/var/tmp/python27-2.7.1-1.wt_el5-root-hans/usr/lib/python2.7/struct.py", line 1, in <module>
    from _struct import *
ImportError: No module named _struct

I have cleaned out and rebuilt this many times.  I'm going to continue digging to see if I can figure out how to get the the .so files in the right place (or put the right dir on the path).  I'm also curious what changed from version 2.6 in this regard (and hopefully I'll figure it out with some more work).