CreateVolume API response doesn't match AWS EC2

Currently the response looks like:
<?xml version="1.0" ?><CreateVolumeResponse xmlns="http://ec2.amazonaws.com/doc/2011-02-28/"><requestId>7I8G7FE0IROF2VLX-JTX</requestId><volumeSet><item><status>creating (atomiadev, None, None, None)</status><availabilityZone>nova</availabilityZone><displayName/><volumeId>vol-00000003</volumeId><displayDescription/><attachmentSet><item/></attachmentSet><createTime>2011-04-20T11:05:47Z</createTime><size>1</size></item></volumeSet></CreateVolumeResponse>

According to the API documentation it should be:
<?xml version="1.0" ?><CreateVolumeResponse xmlns="http://ec2.amazonaws.com/doc/2011-02-28/"><requestId>7I8G7FE0IROF2VLX-JTX</requestId><status>creating (atomiadev, None, None, None)</status><availabilityZone>nova</availabilityZone><displayName/><volumeId>vol-00000003</volumeId><displayDescription/><attachmentSet><item/></attachmentSet><createTime>2011-04-20T11:05:47Z</createTime><size>1</size></CreateVolumeResponse>

i.e. remove the volumeSet.