Question about Linux Memory alert

Hi all. I've setup the hobbit-clients.cfg with the following for memory for our linux servers...

PAGE=NY/NY-Linux

MEMPHYS 100 101

MEMSWAP 60 80

MEMACT 90 95

I've done this because the Physical Memory on the linux machines always shows quite high due to Linux's memory management, and thus far its worked great.

But today we started receiving alerts on a host that the physical memory is 99%. The actual memory is only 10% used, so my question is why am I getting alerts on this host.

Thanks,

Taylor