Problems with dynamically created images in popup menus

Poster: Clothlugs
Dated: Friday January 20 2006 - 10:10:48 GMT

Hello,

I am creating an image map based menu system in which I want to show dynamically created images in popup menus. The images are created by using the URL to a Perl CGI script on our server. This work great and the popup menus show the correct images.

The problem I am having is that the images shown on the popup menus appear to be cached and never update after the first open. Subsequent opens of the popup menu show the same image.

The CGI script creating the images is using continuously updating data and the image returned is always different. I can see from the server logs that the CGI script is only accessed the first time the popup menu is opened. So the problem appears to be on the client or with intermediate caching.

The CGI script puts information in the HTTP header so that the image is not cached at the browser or intermediate caching (e.g. a caching web proxy). We have been using this script for several years and this has always worked. So the problem appears to be with the DHTML Menu system.

Any ideas what this could be? Any help would be greatly appreciated.

Super cheers
Duncan