Powershell 2.0 - get-hotfix cmdlet problem

All,

Curious to know if get-hotfix will display the results for any hotfix / patch that's been installed on a workstation / server?  The reason I ask is that I tried to use it to see if a particular Excel 2007 patch had been deployed, but when I run the command it comes back saying:

"This command cannot find hot-fix on machine 'localhost'.  Verify the input and Run your command again."

The command I am running is:

get-hotfix -id KB978382 -ea 3

Now here is the interesting part.  I can look in the View Installed Updates from within Win7 Windows Update, and I see the KB listed there as being installed.

I can get the get-hotfix to work if I put in a different KB which also shows it is installed, but it seems to be hit or miss as to which KB's get-hotfix seems to report on.

Any thoughts?

Thanks,
Sam