by Ken Task.
Just a guess ... given the info shared ... guessing remotely hosted and a Linux flavor of some sort.
Check ownership/permissions on your data folder recursively (is that moodle2 inside the code directory 'moodle'?).
[data]/temp/backup needs to be writable by the web server user.
Also wonder about how much space one has left? Running cron often enough? With version 2 of Moodle, cron must run in order to 'empty the trash'.
'spirit of sharing', Ken