Hi Tigeradmin,
Based on my understanding, you have about 30 computers and you can launch the installed ClickOnce application and upgrade it if there's a newer version on all these computers except 3. If I'm off base, please feel free to let me know.
Ifthere isn't any difference between these 3 problematic computers and others, e.g. the installed OS version and the installation URL of the ClickOnce application, I suspect the problem is caused by the user profile of the user that installed the ClickOnce application.
You may have a try like this - uninstall the ClickOnce application from the problematic computers anddelete that user's profile(%systemdir% \users\username or %systemdir%\Documents and Settings\username). Log onthe computer as that userand then reinstall the ClickOnce application again to see if the problem is fixed.
Hope this helps.
Sincerely,
Linda Liu