I am trying to integrate google checkout with my website. I downloaded the sample files from google (classic asp) but am getting an xml error

Code:
<?xml version="1.0" encoding="UTF-8"?>
<error xmlns="http://checkout.google.com/schema/2" serial-number="8eafea9c-93fa-41c2-8cab-06def92eb3db">
  <error-message>Error parsing XML; message from parser is: cvc-elt.1: Cannot find the declaration of element 'checkout-shopping-cart'.</error-message>
</error>
The xml generated is

Code:
<?xml version="1.0" encoding="UTF-8"?>
  <checkout-shopping-cart xmlns="http://sandbox.google.com/schema/2">
    <shopping-cart>
      <items>
        <item>
          <item-name>MegaSound 2GB MP3 Player</item-name>
          <item-description>Portable MP3 player - stores 500 songs</item-description>
          <unit-price currency="GBP">178</unit-price>
          <quantity>1</quantity>
          <merchant-private-item-data><color>blue</color><weight>3.2</weight></merchant-private-item-data>
          <item-weight unit="LB" value="5.5" />
        </item>
        <item>
          <item-name>Dry Food Pack AA1453</item-name>
          <item-description>A pack of highly nutritious dried food for emergency.</item-description>
          <unit-price currency="GBP">35</unit-price>
          <quantity>1</quantity>
          <merchant-item-id>JMACC012</merchant-item-id>
          <tax-table-selector>food</tax-table-selector>
          <item-weight unit="LB" value="6" />
        </item>
      </items>
      <merchant-private-data><session-id>Session123</session-id><cart-id>Cart123</cart-id></merchant-private-data>
    </shopping-cart>
    <checkout-flow-support>
      <merchant-checkout-flow-support>
        <edit-cart-url>http://www.example.com/edit</edit-cart-url>
        <continue-shopping-url>http://www.example.com/continue</continue-shopping-url>
        <request-buyer-phone-number>true</request-buyer-phone-number>
        <shipping-methods>
          <flat-rate-shipping name="UPS Ground">
            <price currency="GBP">5</price>
            <shipping-restrictions>
              <allow-us-po-box>false</allow-us-po-box>
              <allowed-areas>
                <us-country-area country-area="CONTINENTAL_48" />
                <us-state-area>
                  <state>CA</state>
                </us-state-area>
                <us-state-area>
                  <state>AZ</state>
                </us-state-area>
                <us-state-area>
                  <state>OR</state>
                </us-state-area>
                <us-state-area>
                  <state>WA</state>
                </us-state-area>
                <us-zip-area>
                  <zip-pattern>9404*</zip-pattern>
                </us-zip-area>
                <us-zip-area>
                  <zip-pattern>94086</zip-pattern>
                </us-zip-area>
                <us-zip-area>
                  <zip-pattern>91801</zip-pattern>
                </us-zip-area>
                <us-zip-area>
                  <zip-pattern>91362</zip-pattern>
                </us-zip-area>
                <postal-area>
                  <country-code>GB</country-code>
                  <postal-code-pattern>SW*</postal-code-pattern>
                </postal-area>
              </allowed-areas>
            </shipping-restrictions>
          </flat-rate-shipping>
          <carrier-calculated-shipping>
            <carrier-calculated-shipping-options>
              <carrier-calculated-shipping-option>
                <price currency="GBP">10</price>
                <shipping-company>FedEx</shipping-company>
                <shipping-type>Priority Overnight</shipping-type>
                <carrier-pickup>REGULAR_PICKUP</carrier-pickup>
                <additional-fixed-charge currency="GBP">5.0</additional-fixed-charge>
                <additional-variable-charge-percent>1.10</additional-variable-charge-percent>
              </carrier-calculated-shipping-option>
            </carrier-calculated-shipping-options>
            <shipping-packages>
              <shipping-package>
                <height unit="IN" value="6" />
                <length unit="IN" value="24" />
                <width unit="IN" value="15" />
                <delivery-address-category>RESIDENTIAL</delivery-address-category>
                <ship-from id="ABC">
                  <city>New York</city>
                  <region>NY</region>
                  <country-code>US</country-code>
                  <postal-code>10022</postal-code>
                </ship-from>
              </shipping-package>
            </shipping-packages>
          </carrier-calculated-shipping>
        </shipping-methods>
        <tax-tables>
          <default-tax-table>
            <tax-rules>
              <default-tax-rule>
                <rate>0.0825</rate>
                <tax-area>
                  <us-state-area>
                    <state>CA</state>
                  </us-state-area>
                </tax-area>
              </default-tax-rule>
              <default-tax-rule>
                <rate>0.0825</rate>
                <tax-area>
                  <us-state-area>
                    <state>NY</state>
                  </us-state-area>
                </tax-area>
              </default-tax-rule>
              <default-tax-rule>
                <rate>0.075</rate>
                <tax-area>
                  <us-country-area country-area="ALL" />
                </tax-area>
              </default-tax-rule>
            </tax-rules>
          </default-tax-table>
          <alternate-tax-tables>
            <alternate-tax-table name="food">
              <alternate-tax-rules>
                <alternate-tax-rule>
                  <rate>0.05</rate>
                  <tax-area>
                    <us-state-area>
                      <state>CA</state>
                    </us-state-area>
                  </tax-area>
                </alternate-tax-rule>
                <alternate-tax-rule>
                  <rate>0.05</rate>
                  <tax-area>
                    <us-state-area>
                      <state>NY</state>
                    </us-state-area>
                  </tax-area>
                </alternate-tax-rule>
                <alternate-tax-rule>
                  <rate>0.03</rate>
                  <tax-area>
                    <us-country-area country-area="FULL_50_STATES" />
                  </tax-area>
                </alternate-tax-rule>
              </alternate-tax-rules>
            </alternate-tax-table>
          </alternate-tax-tables>
        </tax-tables>
        <rounding-policy>
          <mode>CEILING</mode>
          <rule>TOTAL</rule>
        </rounding-policy>
      </merchant-checkout-flow-support>
    </checkout-flow-support>
    <order-processing-support>
      <request-initial-auth-details>true</request-initial-auth-details>
    </order-processing-support>
  </checkout-shopping-cart>
I posted this onto the google help but have had no replies so thought I would try the helpful folks here if any of you have integrated google checkout before.

Eventually what I want to do is

user selects products (I have done this)
basket goes into a database (done)
send a basket to google (done pre using the google sample code and html method)
google sends notification back to add a flag to database to say the order can be fulfilled
the basket then shows up in my basket admin
once order has been dispatched I press a button in my admin and it charges the order via google

Has anyone done this with google checkout?