Firewall2 log problem

Hi list, I just found strange problem on my server. I run Susefirewall2 on 7.3, and i just found that since 3 days ago my firewall didn't write the log to /var/log/firewall and the file size is 0. I try touch firewall to that file but still don't work. I remember that several days ago I gz the file manually, and remove the old firewallxxxxxx.gz to save space. Was it the cause? Can anybody give the clue? TIA Edwin