Should work with debian also.
Ubuntu 10.04.4 LTS x32 system fully patched with LAMP, SSH, and Samba already installed
* Installed samba via the webmin interface

Install the local syslog server
apt-get install sysklogd

Edit the syslog server
nano /etc/syslog.conf

local7.* /var/log/samba/log.audit

Save and exit
touch /var/log/samba/log.audit
/etc/init.d/sysklogd restart

Edit Samba to enable the logging
nano /etc/samba/smb.conf

vfs objects = full_audit
full_audit:prefix = %u|%I|%m|%S
full_audit:success = mkdir rename unlink rmdir pwrite
full_audit:failure = none
full_audit:facility = LOCAL7
full_audit:priority = NOTICE

Save and Exit
/etc/init.d/smbd restart

You should now notice the file attempts at /var/log/samba/log.audit