Memory oveflow in windows server 2008

Hi,

We have a problem monitoring RAM memory in WIndows Servers 2008 with NSCLIENT++ . Checks are performed without problems and results are what we expect.

Although, the perf data registerd has peaks more than 100%

http://img411.imageshack.us/img411/6933/perfdata1.jpg

Mostly of time, nagios recieves normal perfdata: ‘physical memory’=96%;95;101;

Does anyone know what is happening? Are we having some kind of overflow for some reason? Anyway we can solve this?

Thanks a lot.

Alex.