Cannot access SBS SharePoint from outside domain (or inside using hostname)

Given all the attention to this here, I hate to even ask the question.  But I haven't found any answers, so here I go:

I've got a new installation of SBS 2008 Premium.  Although it was a 2003 migration, I didn't move any SharePoint data over -- started from scratch.

I cannot access the "Internal Website" from the main RWW screen, meaning I've got no access to SharePoint from outside the domain.  Some particulars:

*Can logon from outside domain and get access to remote mail and desktop connections -- all of which use https.  Just can't get into the SharePoint Site;
* When I try to connect to the "Internal Website," the browser hangs for a while before giving just a blank screen -- no error 404 or redirect to somewhere else.
* Firewall is a Pix5e configured for HTTPS access, which should implicitly open port 987.  When I try to configure JUST that port, it says it's already configured that way.
*  I've added every possible configuration in various browsers to assure their "trusted."
* I've reviewed the bindings and authorizations for the sites, all of which seem to work.
* I can get access to the site from the server when I use "localhost" or the server's IP.  (However, I can't replicate that when I RDP from home.  I figure it's a remote thing.)

I've spent HOURS trying to make this work.  Despite all the wonderful comments here about many related issues, none of the solutions have been applicable or successful.

Any thoughts?