by Peter Bowen.
You may actually need to modify the permissions for the web host to be able to write to the directories.
In our environment, I use the following commands to give the appropriate access. Once this is done, it works a treat. (I use it for blowing away and recreating my DEV environment on a regular basis)
sudo chown -R root:apache /home/starnurs/mdata/data/{cache,filedir,lang,temp}
sudo chmod -R g+rw,o-rwx /home/starnurs/mdata/data/{cache,filedir,lang,temp}
Cheers
Peter