Hi, how can I use rrdupdate to zero out certain older values stored by mrtg (Interval: 5 minutes) ? # rrdtool update 10.11.12.13.rrd 1198568400:U:U ERROR: illegal attempt to update using time 1198568400 when last update time is 1198568934 (minimum one second step) # No matter which older value I try I get that message. Thank you.