ipvsadm from cron ?

[Olivier Bonvalet <olivier.bonvalet@xxxxxxxxxx>]

Hello,

I'm trying to change the weight of some real servers in cron, because 
they have some "heavy" tasks.
So, some minutes before this tasks, I set to put the weight to 0, with 
lines like this one :
   45-59 23 * * 1 root /sbin/ipvsadm -e -t VIP:80 -r real1.hostname.tld 
-i -w 0
This command works perfectly in command line, but when started from 
cron, it have no effect.
In logs, I see only this :
   Apr 24 23:45:01 LB1 /USR/SBIN/CRON[22494]: (root) CMD (/sbin/ipvsadm 
-e -t VIP:80 -r real1.hostname.tld -i -w 0)
Is there any restriction, or did I do a mistake ?

Thanks in advance,
Olivier