have no clou why the .tmp file is created.. but - although this is obvious - have you checked if the webserver has the right to create (new) files within the settings/siteaccess/main/ directory? check the permissions of the ../main/ folder.
[quote]
but - although this is obvious - have you checked if the webserver has the right to create (new) files within the settings/siteaccess/main/ directory? check the permissions of the ../main/ folder. [/quote]
Yes, one would think that would be obvious. :)
You are, of course, entirely correct. Changing permissions for the main/ dir resolved the issue.