Thanks to one member I've seen the content of the PHP file being offered for download, and the very first thing I noticed was that the version matched the previous version before the forum software upgrade.
This means it's not the CC server that is causing the issue; it's either a web browser issue, or an ISP caching issue.
With particular reference to AOL, it only seems to be a problem if you use the AOL branded browser. If you connect to AOL, but then use the standard desktop version of IE it works okay.
I don't know if this is the case for other people who are experiencing problems as I've only had one emailed PHP file, but if it is the main cause then I assume that ISP's will update their web-cache at fairly regular intervals and the problem will eventually go away as the cached copy of the PHP files are replaced with the latest versions.
If you are still experiencing problems with a "download" where you should be seeing a forum page, please email me the PHP file so I can see if there are any other additional problems that need looking at.
Thanks,
Shaun