thetao,
I am not familiar with the software but I can recommend this:
Browse the page(s) wher eyou see the broken link, right click it and click properties.
Take a look at the PATH and FILENAME in the URL for the image.
Copy & paste it into your browser, and see if the image works that way.
If its in a folder called /icons there MAY be some Virtual Folder or the sort associated with Apache, in fact I believe there is.
You can definitely tell if this is the case by removing the filename from the copied path & filename, and try to browse the folder.
You can also place an erroneous file (a readme.txt of sort) in that folder via FTP and try to access it.
You can tehn see if its a permission issue as well.
if it comes up 404, and you are sure that txt file is there, it must be a path problem.
If it comes up with an unauthorized, you may need to set folder permissions, which is dependent on the web server software.