I'm using Excel 2003 in high security mode. I've generated a certificate
using selfcert.exe, signed a spreadsheet with a macro, saved and then reopend
it. When I open the file, I get the Security Warning dialog box and the only
thing I can do is disable the macro because "Always trust macros from this
publisher" is greyed out.

This is all being done on the same computer as the same user. When I choose
Tools | Macro | Security, "Trust access to Visual Basic Project" is checked,
but greyed out too. If I and manually export the certificate and then import
it into "Trusted Publishers", the macro will run, but I'm trying to come up
with a simpler process for some of my less sophisticated users.