mod_bw won't work

[Yuriy]

hi, i installed mod_bw on plesk, added the following commands to vhost.conf and vhost_ssl.conf
<IfModule mod_bw.c>
BandWidthModule On
ForceBandWidthModule On
BandWidth all 4000000000
MinBandwidth all -1
MaxConnection all 1
</IfModule>

but it doesn't work
this is the position of files: /var/www/vhosts/system/dl.domain.org/conf/vhost.conf and /var/www/vhosts/system/dl.domain.org/conf/vhost_ssl.conf

also, if i read the file /var/www/vhosts/system/dl.domain.org/conf/httpd.conf
i get 2 <VirtualHost>, the first have the commands from vhost.cont, the second not.

the first lines
<VirtualHost XXX.XXX.XXX:7081 >
ServerName "dl.domain.org:443"
[here there are other standard commands.....]
BandWidthModule On
ForceBandWidthModule On
BandWidth all 4000000000
MinBandwidth all -1
MaxConnection all 1
</VirtualHost>

the second
<VirtualHost XXX.XXX.XXX:7080 >
ServerName "dl.domain.org:80"
[here there are other standard commands.....]
</VirtualHost>

i did something wrong? how can i resolve this problem?