Problem with NSClient

Hi Team,

I have installed NSClient on around 12 system and and I am getting perfect result for all system excluding one where i get below error for memory check and for the same server other check (DISK, CPU, etc ) is working fine.

Memory usage: total:0.00 Mb - used: 0.00 Mb (nan%) - free: 0.00 Mb (nan%) | ‘Memory usage’=0.00Mb;0.00;0.00;0.00;0.00

I have nagios 3.2.1 on Centos 5.4 with nagios pluging 1.4.2
I have installed NSClient 2.01

Thanks & Regards,
JITENDRA