Here my request:
Content-Type: text/xml; charset=utf-8
Authorization: Bearer XXXXXXXXXXXXXXXXXXX
SOAPAction: ""
Content-Length: 1991
Expect: 100-continue
Accept-Encoding: gzip, deflate
<s:Header>
<clientCustomerId>XXXXXXXXX</clientCustomerId>
<developerToken>XXXXXXXX</developerToken>
<userAgent>XXXXXXXXX</userAgent>
<validateOnly>true</validateOnly>
</h:RequestHeader>
</s:Header>
<operations>
<operator>ADD</operator>
<operand xsi:type="BiddableAdGroupCriterion">
<adGroupId>21778922962</adGroupId>
<criterion xsi:type="ProductPartition">
<id>-1</id>
<partitionType>SUBDIVISION</partitionType>
</criterion>
<biddingStrategyConfiguration>
<bids xsi:type="CpcBid">
<bid>
<microAmount>10000</microAmount>
</bid>
</bids>
</biddingStrategyConfiguration>
</operand>
</operations>
<operations>
<operator>ADD</operator>
<operand xsi:type="BiddableAdGroupCriterion">
<adGroupId>21778922962</adGroupId>
<criterion xsi:type="ProductPartition">
<partitionType>UNIT</partitionType>
<parentCriterionId>-1</parentCriterionId>
<caseValue xsi:type="ProductOfferId">
<value>10</value>
</caseValue>
</criterion>
<biddingStrategyConfiguration>
<bids xsi:type="CpcBid">
<bid>
<microAmount>10000</microAmount>
</bid>
</bids>
</biddingStrategyConfiguration>
</operand>
</operations>
<operations>
<operator>ADD</operator>
<operand xsi:type="BiddableAdGroupCriterion">
<adGroupId>21778922962</adGroupId>
<criterion xsi:type="ProductPartition">
<partitionType>UNIT</partitionType>
<parentCriterionId>-1</parentCriterionId>
<caseValue xsi:type="ProductOfferId"/>
</criterion>
<biddingStrategyConfiguration>
<bids xsi:type="CpcBid">
<bid>
<microAmount>10000</microAmount>
</bid>
</bids>
</biddingStrategyConfiguration>
</operand>
</operations>
</mutate>
</s:Body>
</s:Envelope>
RESPONSE (PRODUCT_PARTITION_DOES_NOT_EXIST is only a consequence of INVALID_BID):
HTTP/1.1 500 Internal Server Error
Content-Type: text/xml; charset=UTF-8
Date: Mon, 27 Jul 2015 16:56:26 GMT
Expires: Mon, 27 Jul 2015 16:56:26 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
Server: GSE
Accept-Ranges: none
Vary: Accept-Encoding
Content-Length: 2746
<soap:Header>
<requestId>00051bde3be7fbf10a0dd4029908a1db</requestId>
<serviceName>AdGroupCriterionService</serviceName>
<methodName>mutate</methodName>
<operations>0</operations>
<responseTime>891</responseTime>
</ResponseHeader>
</soap:Header>
<soap:Body>
<soap:Fault>
<faultcode>soap:Server</faultcode>
<faultstring>[BiddingErrors.INVALID_BID @ operations[0].operand.biddingStrategyConfiguration.bids; trigger:'CpcBid{bid=0.010000, contentBid=null, cpcBidSource=null}', AdGroupCriterionError.PRODUCT_PARTITION_DOES_NOT_EXIST @ operations[1].operand.criterion.parentCriterionId; trigger:'TempCriterionId{id=1}', AdGroupCriterionError.PRODUCT_PARTITION_DOES_NOT_EXIST @ operations[2].operand.criterion.parentCriterionId; trigger:'TempCriterionId{id=1}']</faultstring>
<detail>
<message>[BiddingErrors.INVALID_BID @ operations[0].operand.biddingStrategyConfiguration.bids; trigger:'CpcBid{bid=0.010000, contentBid=null, cpcBidSource=null}', AdGroupCriterionError.PRODUCT_PARTITION_DOES_NOT_EXIST @ operations[1].operand.criterion.parentCriterionId; trigger:'TempCriterionId{id=1}', AdGroupCriterionError.PRODUCT_PARTITION_DOES_NOT_EXIST @ operations[2].operand.criterion.parentCriterionId; trigger:'TempCriterionId{id=1}']</message>
<ApplicationException.Type>ApiException</ApplicationException.Type>
<fieldPath>operations[0].operand.biddingStrategyConfiguration.bids</fieldPath>
<trigger>CpcBid{bid=0.010000, contentBid=null, cpcBidSource=null}</trigger>
<errorString>BiddingErrors.INVALID_BID</errorString>
<ApiError.Type>BiddingErrors</ApiError.Type>
<reason>INVALID_BID</reason>
</errors>
<fieldPath>operations[1].operand.criterion.parentCriterionId</fieldPath>
<trigger>TempCriterionId{id=1}</trigger>
<errorString>AdGroupCriterionError.PRODUCT_PARTITION_DOES_NOT_EXIST</errorString>
<ApiError.Type>AdGroupCriterionError</ApiError.Type>
<reason>PRODUCT_PARTITION_DOES_NOT_EXIST</reason>
</errors>
<fieldPath>operations[2].operand.criterion.parentCriterionId</fieldPath>
<trigger>TempCriterionId{id=1}</trigger>
<errorString>AdGroupCriterionError.PRODUCT_PARTITION_DOES_NOT_EXIST</errorString>
<ApiError.Type>AdGroupCriterionError</ApiError.Type>
<reason>PRODUCT_PARTITION_DOES_NOT_EXIST</reason>
</errors>
</ApiExceptionFault>
</detail>
</soap:Fault>
</soap:Body>
</soap:Envelope>