This is probably a mysql problem as you said. But I still don’t know what. Can you do a php info and see : What Apache version do you use? What PHP version and what mysql?
Debian http://dl.dropbox.com/u/2891468/phpinfo-debian.pdf (dont’t work)
Ubuntu http://dl.dropbox.com/u/2891468/phpinfo-ubuntu.pdf (works!)when i do in phpmyadmin debian “insert into table(x,y,z) values(1,2,3)” and the table definition has (x,y,z,w) don’t work. BUT when i do the same in ubuntu the insert was
done and w has a default value.
Perhaps is the Suhosin Extension . Try to disable it and try again , then try to disable only the features of the sql .I am not sure but is the only thing that it seems wrong. With a quick google search I find that this extension blocks some queries to avoid SQl injections. In CI there is not such a problem, because every query goes first to the validation check of the active record.