I think the default port for new Windows installations of Subsonic should be changed to 4040 instead of 80. This would keep it in line with the Mac and Linux installs which will make troubleshooting easier, but more importantly many ISP's block port 80.
This has caused problems for multiple people I've helped. They have everything set up correctly and it's just not working, then we change the port from 80 to anything non-standard and it works fine. But that's just one more step that can make the installation difficult for some people.
Any thoughts?