[mod_python] Session problems

I am trying to convert a program (see below) written for the
BaseHTTPServer to Apache and am getting a MemoryError trying to save the
session.  Is there a trick to this I am missing?  Thanks!  harry

from mod_python import apache, util, Session
import sys, urllib, urlparse, xml.dom.pulldom, cgi, socket,
xml.sax.saxutils, StringIO, math, glob, os.path, ddc3

def handler(req):
	sess = Session.Session(req)
	ddcServer = DDCServer(req)
	ddcServer.root = ddcServer.req.document_root()
	oclc2ddcFile = ddcServer.root + '/Collections/eBooks.ddc'
	recFileName = ddcServer.root + '/Collections/eBooks.ddc.ulines'
	compHoldingsFile = ddcServer.root + '/ihbnum.compressed'
	captionsFile = ddcServer.root + '/Captions'
	ddcServer.testing = 0
	if sess.is_new():
		req.write("Session is new\n")
		ddcServer.captions = DDCCaptions(captionsFile)
		ddcServer.localText = TextLocalization(captionsFile)
		ddcServer.ddcSearch = ddc3.DDCSearch(file(oclc2ddcFile),
recFileName, file(compHoldingsFile, 'rb', 100000))
		try:
			sess['captions'] = ddcServer.captions
			sess['localText'] = ddcServer.localText
			sess['ddcSearch'] = ddcServer.ddcSearch
			sess.save()
			sess.unlock()
			req.write("Session saved\n")
		except MemoryError: req.write("MemoryError raised\n")
	elif not sess.is_new():
		sess.load()
		req.write("Previous session loaded\n")
		ddcServer.captions = sess['captions']
		ddcServer.localText = sess['localText']
		ddcServer.ddcSearch = sess['ddcSearch']
		req.write("data has finished loading\n")
#	ddcServer.do_GET()
	return apache.OK

-------
Session is new
MemoryError raised