you aren't doing anything wrong. We have just started releasing 64 bit dups, but there are many devices that don't have 64 bit dups yet, so that the reason for the message. Please continue to use the 32 bit dups, there will be no difference. The 64 bit dups were designed to run in 64bit OSs only, but 32 bit dups will run fine on 64 bit OS's. 
Just updated to the latest (1.7.0.158) and it now has a choice when downloading an SUU to choose between 32 and 64 bit Windows for a model of blade. So, I choose m710HD and try and choose Windows 64 bit, but Rep Manager says: "There are no bundles in the current view. The repository either does not contain any bundles or filter criteria is too restrictive." 32 bit works fine. What am I doing wrong to cause the above message? Thx John Bradshaw  [IMAGE]
Dell Repository Manager