[Zope] Adding objects

Hi all, I've setup Zope and am attempting to add objects but keep getting this message: Server Error The server has encountered an error while publishing this resource. Error Type: IOError Error Value: Can't find a usable temporary directory amongst ['/usr/tmp', '/tmp', '/usr/zope/Zope-2.0.1-linux2-x86'] I'm sure it's a fairly simple problem. I've checked the directories which are all present and even tried changing permissions to user nobody but nothings made any difference. Does anyone have any ideas? Thanks Chris