I am trying to be able to call some methods like UpdateItem and have not been successful. I keep getting the following error: 

Exception: imported schema (http://www.w3.org/XML/1998/namespace) at (http://www
.w3.org/2001/xml.xsd), failed

If someone could post some working code that creates a client and successfully calls a method I would greatly appreciate it. Thank you. I read somewhere that downloading the schema file locally onto my pc could help, but I'm not sure how to implement that in my code either. Here is what I have so far:

```
import urllib2
import suds
import logging
from suds import WebFault
from suds.client import Client
from suds.client import Factory
from suds.transport.http import HttpAuthenticated
from logging import getLogger
logging.getLogger('suds.client').setLevel(logging.CRITICAL)
from suds.xsd.doctor import ImportDoctor, Import

# cannot access schema through browser
imp = Import('http://schemas.microsoft.com/exchange/services/2006/messages')
d = ImportDoctor(imp)
client = Client('http:path to wsdl', doctor = d, username='my_username',       
password='my_password')
retVal = client.service.GetServerTimeZones()
print retVal

```