Backup and restore

Hi there,

I'm having problems with my moodle 1.7.1 backups - but not always. I've been trying out different things, including stuff suggested here in the forum, but cannot make the backups work 100%, so I hope you can give me some new ideas...

1. Scheduled backups run into error. The logfiles do not state any error, it seems as if the procedure is "stuck" somewhere. Unfortunately, in different places for each of my courses:
a) after "general info"
b) after "user info"
c) after "user info"
d) no logs found

2. Manual backups sometimes work, sometimes not. I tried out a lot of different variations, here's the summary:
Working (always without logfiles):
- only user data (no modules selected)
- only the assisgnment data
- only the forum data
- only the hot potato module data
- the whole course except forum, chat, hotpotato modules

Not working:
- any combination including logfiles so far
- whole course without chat & hotpotato modules (w/o logfiles)
- chat module only (w/o logfiles)

At first I thought it was a size issue, so I changed the .htaccess lines into:
php_value upload_max_filesize 100M
php_value post_max_size 5M
php_value session.gc_maxlifetime 72000

But it's weird that the chat backup only is not working - it shouldn't be bigger than e.g. the assignment, where there's much more text and pics. And why could the logfiles be such a problem?

Any ideas and even wild guesses are highly appreciated!

Best regards
Sandra

PS: moodle 1.7.1, on a hosted Linux machine, mysql