Report doubles in Size

We have two reports that work just fine. 

They essentially do the same thing, only one reports on running configs and the other on startup configs, and specifically shows the last time that type of config was run. In an attempt to rationalise these reports into one, I just removed the part from my report that restricts it to run/start and whilst the report runs it has doubled in size. It has gone from 70k lines to >140K

At first glance you'd think that sounds reasonable if every device has a startup and a running config, but for example, one FW has reported back 106 times. In looking at the output it now appears to be showing all the backups ever taken for that device and their dates, rather tan just the last.

Any suggestions on what's wrong with the following or how I fix it please?

SELECT OrionNodes.Caption, OrionNodes.DetailsUrl, OrionNodes.Status, OrionNodes.ChildStatus, 
OrionNodes.Vendor, OrionVendors.Icon, OrionNodes.IP_Address, OrionNodes.IPAddressType, 
OrionNodes.MachineType, NcmConfigArchive.DownloadTime, NcmConfigArchive.ConfigType   

FROM NCM.NodeProperties AS NcmNodeProperties  
INNER JOIN Orion.Nodes AS OrionNodes ON NcmNodeProperties.CoreNodeID=OrionNodes.NodeID  
INNER JOIN Orion.Vendors AS OrionVendors ON OrionNodes.Vendor=OrionVendors.Name  
LEFT JOIN NCM.ConfigArchive AS NcmConfigArchive ON NcmNodeProperties.NodeID=NcmConfigArchive.NodeID 

-- AND NcmConfigArchive.ConfigType ANY
-- The above is the only chage from teh original and is the line that I commented out

INNER JOIN Orion.NodesCustomProperties AS OrionNodesCustomProperties ON OrionNodes.NodeID = OrionNodesCustomProperties.NodeID

WHERE OrionNodesCustomProperties.Node_in_BAU = True