Solaris 10 x86 Client mis-reporting available disk space

I've just installed xymon latest onto a Solaris X86 client, and it is reporting warning levels of 90% disk use, when in fact the machine is only at 60%.

I've been unable to find where and how this is defined/set, and same goes for swap and CPU (although these two ARE NOT a problem right now).

Thank you in advance,

.vp