I am facing the same issue. I am trying my request from SOAPUI
As suggested by you i am not using any sub zero second precision
Response from export definition:
<Response xmlns="https://secure.eloqua.com/api/bulk/2.0/activities/exports">
<createdAt>2014-08-28T22:00:40.5537126Z</createdAt>
<createdBy>Eloqua</createdBy>
<fields>
<ActivityDate>{{Activity.CreatedAt}}</ActivityDate>
<ActivityId>{{Activity.Id}}</ActivityId>
<ActivityType>{{Activity.Type}}</ActivityType>
<AssetId>{{Activity.Asset.Id}}</AssetId>
<AssetName>{{Activity.Asset.Name}}</AssetName>
<AssetType>{{Activity.Asset.Type}}</AssetType>
<ContactId>{{Activity.Contact.Id}}</ContactId>
<Id>{{Activity.Id}}</Id>
<RawData>{{Activity.Field(RawData)}}</RawData>
<VisitorId>{{Activity.Visitor.Id}}</VisitorId>
</fields>
<filter>'{{Activity.Type}}'='FormSubmit' And '{{Activity.CreatedAt}}'>'2014-08-26T00:00:00'</filter>
<name>Example Activity Export</name>
<updatedAt>2014-08-28T22:00:40.5537126Z</updatedAt>
<updatedBy>Eloqua.APIUser1</updatedBy>
<uri>/activities/exports/36</uri>
</Response>
-------------------------------------
Response Sync the data for export
<Response xmlns="https://secure.eloqua.com/api/bulk/2.0/activities/exports">
<createdAt>2014-08-28T22:03:05.0953641Z</createdAt>
<createdBy>Eloqua</createdBy>
<status>pending</status>
<syncedInstanceUri>/activities/exports/36</syncedInstanceUri>
<uri>/syncs/16</uri>
</Response>
--------------------------------------------
GET https://secure.eloqua.com/api/bulk/2.0/syncs/16 to check the status of sync
<Response xmlns="https://secure.eloqua.com/api/bulk/2.0/activities/exports">
<createdAt>2014-08-28T22:03:04.8630000Z</createdAt>
<createdBy>Eloqua</createdBy>
<status>error</status>
<syncStartedAt>2014-08-28T22:03:14.4970000Z</syncStartedAt>
<syncedInstanceUri>/activities/exports/36</syncedInstanceUri>
<uri>/syncs/16</uri>
</Response>
--------------------------------------------
Logs.
<Response xmlns="https://secure.eloqua.com/api/bulk/2.0/activities/exports">
<count>2</count>
<hasMore>false</hasMore>
<items>
<e>
<count>0</count>
<createdAt>2014-08-28T22:03:16.4330000Z</createdAt>
<message>There was an error processing the export.</message>
<severity>error</severity>
<statusCode>ELQ-00107</statusCode>
<syncUri>/syncs/16</syncUri>
</e>
<e>
<count>0</count>
<createdAt>2014-08-28T22:03:16.4670000Z</createdAt>
<message>Sync processed for sync 16, resulting in Error status.</message>
<severity>information</severity>
<statusCode>ELQ-00101</statusCode>
<syncUri>/syncs/16</syncUri>
</e>
</items>
<limit>1000</limit>
<offset>0</offset>
<totalResults>2</totalResults>
</Response>
Kindly help
Thanks
Vinay