These aren't explicitly files of data, rather a pointer to a database that collects the first 'x' (in the current case 5) articles related to that category.
If you are having similar problems, please write in as much detail as to when/what/how it occurs.
In these instances, an error popup window occurs with that big red cross on the left. (I can't take a snapshot of the picture here in the lounge, unfortunately) and it reads “Internet Explorer cannot open the Internet site http://www.ata-wa.org.au/news/. Operation aborted” and a single selectable button “ok”.
It is found that the particular category page contained an article with a video embedded in it. There is a conflict between the flash video player and “lightview-plus” plugin. Hence, some pages will work (the ones with no videos in any of the displayed articles) and others not.
Hence, “lightview-plus” has been deactivated as discussed here.