> Err, really weird. I tried to reproduce the issue,
> but I couldn't get images renamed into html files.
> The fact images seems to work means that the server
> successfully delivered the content, and hence the
> images should be correctly named.. however, I got
> some "Service Unavailable" while downloading content
> at geocities - there might be some protection
> against offline browsers.

Ah, I got numerous .html files that were supposed to be .gif files, *BUT*
these files contained actually error messages:

"The web site you are trying to access has exceeded its allocated data
transfer. Visit our help area for more information. Access to this site will
be restored within an hour. Please try again later."

So I guess that geocities has a quite limited bandwidth policy.. try to use
really low download settings, such as 1KB/s, and only one simultaneous
connection, to avoid any "quota limit".