Bandwidth monitoring not working

I have turned on bandwidth monitoring for a couple of virtual servers in Virtualmin, but it is not working. Both still show 0 bytes of usage, despite there being traffic on both domains. I really have no idea where to check to correct this problem. Any ideas on where to start?

Thanks,
jeff

Ok, quick update - I ran the bw.pl script manually and it complained that I didn’t have the proftpd module installed. I re-installed it and then it worked. Does the bandwidth monitoring require proftpd?