We created a report that shows the computers that have firefox installed with windows 7. When we remove the firefox from the computers that are displayed in our report some will be displayed again in  the report after the removing of firefox. How can this happen when we are sure it was removed.
Report query:
Select Top 1000000 tblAssets.AssetID,
  tblAssets.AssetName,
  tsysAssetTypes.AssetTypeIcon10 As icon,
  tblAssets.IPAddress,
  tblAssets.Lastseen,
  tblAssets.Lasttried,
  tblSoftwareUni.SoftwarePublisher,
  tblSoftwareUni.softwareName,
  tblOperatingsystem.Caption,
  tblAssets.Username,
  tblSoftware.SoftwareID,
  tblAssetCustom.State
From tblAssets
  Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
  Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
  Inner Join tblSoftware On tblAssets.AssetID = tblSoftware.AssetID
  Inner Join tblSoftwareUni On tblSoftwareUni.SoftID = tblSoftware.softID
  Inner Join tblOperatingsystem
    On tblAssets.AssetID = tblOperatingsystem.AssetID
Where tblSoftwareUni.softwareName Like '%firefox%' And
  tblSoftwareUni.softwareName Not Like 'Windows Media Player Firefox Plugin' And
  tblOperatingsystem.Caption Like 'Microsoft Windows 7 Enterprise' And
  tblAssetCustom.State != 2
Kind regards,
Litrick