Is this XML valid?

Hi!

I have to validate the xml's signature... Well, with my code the signature is not valid, but supposedly it must be valid... Can anyone validate that and if so, tell me what can i doing wrong... I think the problem is because this XML have three certificates (a certificate chain) and i can be doing the validation in a wrong manner... Please, help me!

The XML File:

<?xml version="1.0" encoding="UTF-8"?><ThreeDSecure><Message id="YL98mU9UYV9QUUpVPVr2"><PARes id="4320750"><version>1.0.2</version><Merchant><acqBIN>410052</acqBIN><merID>500</merID></Merchant><Purchase><xid>WUw5OG1VOVVZVjlRVVVwVlBWcjI=</xid><date>20081111 12:17:51</date><purchAmount>50000</purchAmount><currency>132</currency><exponent>0</exponent></Purchase><pan>0000000000000000</pan><TX><time>20081111 12:08:20</time><status>U</status><cavv>AAACBgeTAgEGWCd2k5MCAAAAAAA=</cavv><eci>05</eci><cavvAlgorithm>2</cavvAlgorithm></TX><IReq><iReqCode>54</iReqCode><iReqDetail>PAReq.Purchase.currency,PAReq.Purchase.exponent</iReqDetail></IReq></PARes><Signature xmlns="http://www.w3.org/2000/09/xmldsig#"><SignedInfo xmlns="http://www.w3.org/2000/09/xmldsig#"><CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"></CanonicalizationMethod><SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"></SignatureMethod><Reference URI="#4320750"><DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"></DigestMethod><DigestValue>o3tL8nr7mwU4pDYuILdF3+f08Ck=</DigestValue></Reference></SignedInfo><SignatureValue>O+r5ZM/BuLRTNRwSg34xlVnHFb38NR/FyL/QpjVeI7dOP+uA4hP37SudiQp66wL7BvYOJ+2awzGq0P6/5aPGCVbziWtJ3GpPVzJJfaRucJP/lj0fD/HV/0j3rcy7Wj2mLnkWO7A5lXFJmkRnegzu+pF/8QnMtjFNQKY9MblTAi4=</SignatureValue><KeyInfo><X509Data><X509Certificate>MIICXTCCAcagAwIBAgIVAPMZwb+MLgbLQyd9hTe+NvF1PFzZMA 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 oWDLMj4p8mIfnreINwDAp3FdyRIrPjIhHorwIDAQABoxAwDjAMBgNVHRMBAf8EAjAAMA0GCSqGSIb3DQEBBQUAA4GBAHYnSqeFWTgELlnod0LbGuhi6WiW+T0xmrJ3ULdEnCcB5lsfJsi1YfgNos1Q+rVLI+d/sfjxvZJZZCWG9AzO9JvOK+i/hH+OUN2l672BMf4oEe318CH4YpfXeF0Mu1QbX2k1Su4YHoCiX0f8SVXCoDV9g64f7p1GysMtULqy01qb</X509Certificate><X509Certificate>MIICHjCCAYegAwIBAgIVAPIEi+mOHBF9HNzSgQd4GHO8bJ95MA0GCSqGSIb3DQEBBQUAMEAxCzAJBgNVBAYTAlVTMRAwDgYDVQQKEwdDYXJhZGFzMQwwCgYDVQQLEwNQSVQxETAPBgNVBAMTCHBpdC1yb290MB4XDTA0MDUwNzE2MjM1M1oXDTE0MDUwNTE 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 QlWfIpAQyoIZbnttWEizhxuLNAbpM4bdfgS/b</X509Certificate><X509Certificate>MIICHzCCAYigAwIBAgIULLsSuNb5wJ0AJ3MkEqaVJe4ayrYwDQYJKoZIhvcNAQEFBQAwQDELMAkGA1UEBhMCVVMxEDAOBgNVBAoTB0NhcmFkYXMxDDAKBgNVBAsTA1BJVDERMA8GA1UEAxMIcGl0LXJvb3QwHhcNMDQwNTA3MTYyMzUwWhcNMTQwNTA1MTYyMzUwWjBAMQswCQYDVQQGEwJVUzEQMA4GA1UEChMHQ2FyYWRhczEMMAoGA1UECxMDUElUMREwDwYDVQQDEwhwaXQtcm9vdDCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAskqbW7oBwM1lCWNwC1obkgj4VV58G1AX7ERMWEIrQQlZ8uFdQ3FNkgMdtmx/XUjNF+zXTDmxe+K/lne+0KDwLWskqhS6 gnkQmxZoR4FUovqRngoqU6bnnn0pM9gF/AI/vcdu7aowbF9S7TVlSw7IpxIQVjevEfohDpn/+oxljm0CAwEAAaMWMBQwEgYDVR0TAQH/BAgwBgEB/wIBATANBgkqhkiG9w0BAQUFAAOBgQBHTNIuf2yS8yDMreO3Ohr1qvTK/jBQkxZdfZbZiba7ItozfAu92tY35iblmElyMgduqmx1XSlbyfuQwXxR1a6Sb3pEN/fFUEyWXqmQuFXEe2KUu5J74tA8SX1fkcI0SNkxbQI4O3pBnmuyIrWAdIRzbM/4QV7yBxXh7g66koit9g==</X509Certificate></X509Data></KeyInfo></Signature></Message></ThreeDSecure>

Thanks a lot,
Cristovao