I got bit by this a while back when developing a program for our users. The solution was to sign the code with a digital cert. Since these were for my users and not the rest of the world, all I had to do was use active directory group policy to insert my self-signed certificate authority into their computer’s “trusted” list. Then I used that CA to create a certificate for myself and used THAT cert to sign all of my code. I’ve even signed required (by not written by me) VBA macros for the various Microsoft Office programs so that I don’t have to drop Zone security levels to use them safely.

I remember reading about a hackish way around this requirement too. It dealt with editing the code access security policy for the computer.
C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\mscorcfg.msc

Traverse to:
My Computer, Runtime Security Policy, Machine, Code Groups, All_Code/LocalIntranet_Zone

It gets fuzzy after this, but I’m sure you can figure it out.