/private/var/log/samba/log.smbd.old weights 122 GB !

some days after having installed leopard, i discovered that my hard-disk is almost full (12 GB left). after counting all the (visible) files there must be at least 130 GB left space. i discovered a hidden file on /private/var/log/samba/log.smbd.old which weights 122 GB (just select "go to folder" in menu "go" of the finder, and write "private": you can then see all the hidden files in this folder). at apple support they don't recommend to remove it, but in the meantime they were not able to tell me the utility of this huge file. they suggest this remedy: backup everything and a clear reinstall of leopard... has anybody experience with removing this file or resolving the problem differently? thx.