You import a new management pack that contains new properties for certain views on a computer that is running System Center Operations Manager 2007 R2. After you do this, you may receive the following error message:
An object of type Variable with ID Number was not found
Additionally, you find that the new properties are missing from a specific view.
To read all the details and to download the hotfix see the following Knowledge Base article:
KB981740 - System Center Operations Manager 2007 R2 does not display new properties in some views after you import a management pack
J.C. Hornbeck | System Center Knowledge Engineer