Weird agent behavoiur (64-bit Windows 2003 R2)

[qix]

I'm having problems on a host which uses 100% of it's CPU.
However, the agent is reporting a strange value :

localhost:/opt/zabbix/zabbix-1.4.4/sbin# ./zabbix_get -s<hostname> -ksystem.cpu.util[,,avg1]
101.666667

How can the CPU utilization percentage be above 100%??