Moneris MPI - Root element invalid.

I'm trying to use curl to do the TXN Request. According to the doc Moneris MPI Verified by Visa / MasterCard SecureCode Transaction DTD v.1.1.1 here's my command.

curl -X POST -d '<?xml version="1.0" encoding="UTF-8"?> <MpiRequest> <store_id>store5</store_id> <api_token>yesguy</api_token> <txn> <xid>00000000001172089875</xid> <amount>4.00</amount> <pan>4242424242424242</pan> <expdate>1912</expdate> <MD>xid=00000000001172089875&pan=4242424242424242&expiry=1912&amount=4.00</MD> <merchantUrl>www.your_domain.com/.../merchantUrl> <accept>text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5</accept> <userAgent>Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.9) Gecko/20061206 Firefox/1.5.0.9</userAgent> <currency></currency> <recurFreq></recurFreq> <recurEnd></recurEnd> <install></install> </txn> </MpiRequest>' "https://esqa.moneris.com/mpi/servlet/MpiServlet"

I tried with store5@yesguy and with moneris@hurgle for store_id and api_token.

I always get the error Root element invalid

What I'm doing wrong?

Thanks

Maxime