I tried creating a report to show all assets which have no department showing.  It is not happening to all assets, but some assets are showing multiple times.  Where did I go wrong in making the report?  All fields show the same information.
Select Top 1000000 tblAssets.AssetID,
  tblAssets.AssetName,
  tsysAssetTypes.AssetTypename As AssetType,
  tsysAssetTypes.AssetTypeIcon10 As icon,
  tblAssets.Domain,
  tsysIPLocations.IPLocation,
  Coalesce(tsysOS.OSname, tblLinuxSystem.OSRelease, tblMacOSInfo.SystemVersion)
  As OS,
  tblOperatingsystem.Caption As [OS Edition],
  tblComputersystem.SystemType,
  tblAssetCustom.Manufacturer,
  tblAssetCustom.Model,
  Cast(Cast(tblAssets.Memory As BigInt) / 1024 As Numeric) As
  [Memory size (GB)],
  tblAssets.Processor,
  tblAssets.Mac As MACAddress,
  tblADComputers.OU,
  tblState.Statename As State,
  tblAssets.Firstseen,
  tblAssets.Lastseen,
  tblAssets.Lasttried,
  tblAssetCustom.PurchaseDate,
  tblAssetCustom.Warrantydate,
  tblAssets.FQDN,
  tblAssetCustom.DNSName,
  tblAssetCustom.Location,
  tblAssetCustom.Department,
  tblAssetCustom.Custom1 As Owner,
  tblAssetCustom.Custom2 As [HW or VM],
  tblAssetCustom.BarCode,
  tblAssetCustom.Contact,
  tblAssetCustom.Serialnumber,
  tblAssetCustom.OrderNumber,
  Case tblAssetCustom.PreventCleanup
    When 0 Then 'No'
    When 1 Then 'Yes'
  End As PreventCleanup,
  tblAssets.Scanserver,
  tblAssets.Username,
  tblADusers.Displayname
From tblAssets
  Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
  Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
  Inner Join tsysIPLocations On tsysIPLocations.LocationID =
      tblAssets.LocationID
  Left Join tblADComputers On tblAssets.AssetID = tblADComputers.AssetID
  Inner Join tblState On tblState.State = tblAssetCustom.State
  Left Join tblLinuxSystem On tblAssets.AssetID = tblLinuxSystem.AssetID
  Left Join tsysOS On tblAssets.OScode = tsysOS.OScode
  Left Join tblMacOSInfo On tblAssets.AssetID = tblMacOSInfo.AssetID
  Left Join tblADusers On tblAssets.Username = tblADusers.Username
  Left Join tblOperatingsystem On tblAssets.AssetID = tblOperatingsystem.AssetID
  Left Join tblComputersystem On tblAssets.AssetID = tblComputersystem.AssetID
  Left Join tblFloppy On tblAssets.AssetID = tblFloppy.AssetID
Where tsysAssetTypes.AssetTypename Not Like 'Monitor' And
  tsysAssetTypes.AssetTypename Not Like 'VOIP%' And tblState.Statename =
  'active' And tblAssetCustom.Department Is Null
Order By tblAssets.AssetName