Well, I'm afraid I know very little about cacheing. However, I
can read headers, and report what I see, in case this is of any help
When I load the new dynamic map, Apache is returning "304 Not Modified", but I'm still downloading the entire set of images. Here's what Safari reports about the headers:
Request URL:http://maps.battlemaster.org/Beluaterra/3/2/2.png
Request Method:GET
Status Code:304 Not Modified
Request Headers
Cache-Control: max-age=0
If-Modified-Since: Wed, 28 Dec 2011 18:07:00 GMT
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/534.52.7 (KHTML, like Gecko) Version/5.1.2 Safari/534.52.7
Referer: http://battlemaster.org/dynamicmap_mini.php?ShowRegion=165.php
Response Headers
Date: Mon, 09 Jan 2012 18:06:16 GMT
Connection: Keep-Alive
Server: Apache/2.2.16 (Debian)
Cache-Control: max-age=604800
Keep-Alive: timeout=10, max=100
Expires: Mon, 16 Jan 2012 18:06:16 GMT