I've had a long struggle looking at all the posts with troubleshooting steps for getting activesync to work on Exchange 2003.
It seems that most of the issues are down to authentication methods on the various subdirectories to the iis default website.
My problem was different- it stemmed from the fact that I often set iis to use a non-default port for http, eg 1080 or 8080.
After a lot of headscratching I came across this post:
And look at comment ID:25499506 ....
I've never come across Microsoft KBs or any other articles besides this one that states you must use port 80 for http, EVEN if you're using activesync over SSL.
And thank god I found it- changing iis to use port 80 on http made my setup work immediately. Nice one alanhardisty :)
So I suppose that SSL is used to tunnel data that is expected to, in turn, talk to an iis app on port 80- can this be changed or is it an inherant restriction? if so, do any later versions of Windows and Exchange also suffer from this limitation? Its also wierd that OWA doesn't have this problem....