AdWords API Error code 88

Ive been having intermitent problems all day.

Returned xml:

soapenv:Envelope
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><soapenv:Body><soapenv:Fault><faultcode>soapenv:Server.userException</faultcode><faultstring>This
request has specified encoding that is not supported.Please check the
http header of your request.</faultstring><detail><ns1:code
xmlns:ns1="https://adwords.google.com/api/adwords/v2">88</ns1:code><ns2:message
xmlns:ns2="https://adwords.google.com/api/adwords/v2">This request has
specified encoding that is not supported.Please check the http header
of your
request.</ns2:message></detail></soapenv:Fault></soapenv:Body></soapenv:Envelope>

This has been working for months and today its working about 10% of the
time.

Any help would be appreciated