Outlook 2007 on Windows 7. Users have had several custom icons in their mailboxes "revert" to default Outlook Icons (Unity VMO and Symantec Enterprise Vault, for instance.) On a machine where this is happening, I go into the customs form area, and can see the forms listed in both the organization forms library and the personal library, but when I highlight each one, no icon is shown in the "preview". On other Win7 machines, where this isn't happening, I can step through the forms and see the icons. Very strange.
I have cleared the cache, and enabled the always update forms reg key on several of these machines, but still no icons and no "preview". Any ideas?