If not please give more information like exactly which version of Moodle, any CVS updates, the host system, size of your installation in terms of number of users, the size of an SQL dump, ...
I remember there was an issue with the backup scripts taking a long time and ultimately overlapping
The point is that Moodle is supposed to do a _lot_, so sometimes hosters who are used to static personal homepages get baffeled by what Moodle demands!