OK- killing the settings files seems to fix the problem. This fix applies for both mac & pc. Re-installing the app doesn't work, as these preference files are kept.
The problem seems to be that the affected machines send back:
Response Headers - http://jira.redant.com.au:XXXX/confluence/pages/listpages.action?key=ds
Cache-Control: no-cache, no-store, must-revalidate
Pragma: no-cache
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Set-Cookie: confluence.browse.space.cookie=listpages; Expires=Mon, 27-Feb-2006 02:44:02 GMT; Path=/confluence
Content-Type: text/html;charset=UTF-8
Content-Length: 0
Date: Fri, 04 Mar 2005 02:44:02 GMT
Server: Apache-Coyote/1.1
Note that the page is "listpages.action?key=ds"
whereas the machines that work fine go to "listpages-dirview.action?key=ds".
If you manually paste in the URL, the affected machines can see the page... so it appears to be something to do with a redirect? Perhaps this is just a weird firefox cache thing when changing over from 1.3 to 1.4, to do with the new space page style ??
Anyway- the fix you suggested has worked. Thanks for your help.
Looks like it was something weird stuck in Firefox's cache