I haven't been able to find a good answer to how to set dependencies that will only run once per workstation.

Here is an example of how I think it should work:

Application A: (a shortcut to "C:\Program Files\Mozilla Firefox\firefox.exe"
When I double click this icon, Application B should be installed, if not already installed. Then open Firefox.

If Firefox has already been installed on the workstation it should just open Firefox.exe

Application B: (an MSI installation of Firefox 2.0)

I can make Application B only run once per workstation by setting a distribution rule, but then Application A won't run because the distribution rule for Application B isn't met.

By default it will onl install Application B once per user, per workstation, but it is unacceptable for a user to have to wait for Firefox to reinstall just because they are on a different workstation.

What am I missing?