[mrtg] About CPU usage

[sachindra]

Dear sir,

I want to poll the cpu usage from  maipu switch and router using mrtg 
but i get error message

2009-09-11 16:46:36: ERROR: Target[2-cpu][_IN_] 
'.1.3.6.1.4.1.5651.3.20.1.1.3.5.1.10. $target->[4]{$mode} ' evaluated to 
'á2615638135' instead of a number
2009-09-11 16:46:36: ERROR: Target[2-cpu][_OUT_] 
'.1.3.6.1.4.1.5651.3.20.1.1.3.5.1.10. $target->[4]{$mode} ' evaluated to 
'á455673716' instead of a number

whose oid value is .1.3.6.1.4.1.5651.3.20.1.1.3.5.1.10.1.

I can get the cpu usage using the snmpwalk