THANK YOU! I mean it, thanks a lot!!! =D
I added "usrjquota=quota.user,grpjquota=quota.group,jqfmt= vfsv0" at /var mountpoint options on /etc/fstab file and:
mount -o remount /var
So I resync using "Ispconfig > Tools > Resync", check all and started. After Jobqueue is complete (I did server.sh and cron_daily.sh using cli), I can now see at "repquota -a" the quotas configured.
Now, I just can't see them at "Ispconfig > Sites > Website quota (harddisk)". Jobqueue is clear, but there's nothing there to be executed. How can I update this page?