I have a MOSS 2007 sharepoint server in my organisation which is published through ISA 2006 to an External URL via HTTPS
External URL: https://sharepoint.contoso.com
Internal URL: http://Sharepoint
the ISA server publishing rule published to HTTPS and the internal site is on HTTP.
the alternate access mappings are set up as follows:
when you click certain links from external (for example moving between pages) , it redirects the resulting screen to http://sharepoint.contoso.com/xxxxxx
obviously this page doesnt come up - if i put in the S in the address bar it goes to the page.