devmon memory threshold issue

hello

it seems that the memory threshold is not working :

threshold is set to 30 and 50 % used

cisco-3750]$ cat memory/thresholds
mem_used_per        : yellow        : 30    : Memory load is high
mem_used_per        : red           : 50    : Memory load is very high


my messages :

[xymon at gdfva-li01 cisco-3750]$ cat memory/message
Memory alert:  yellow={mem_used_per.thresh:yellow}%, red={mem_used_per.thresh:red}%

Free memory:       {mem_free} bytes ({mem_free_per}%)
Used memory:       {mem_used} bytes ({mem_used_per}%)
-------------     ----------------
Total memory:      {mem_total} bytes (100%)

<!-- DEVMON to RRD Physical {mem_used_per}%
-->

my result :

Memory alert:  yellow=30%, red=50%

Free memory:       29814012 bytes (44%)
Used memory:       38625048 bytes (56%)
-------------     ----------------
Total memory:      68439060.00 bytes (100%)


should be red but it's green.

any idee ?

oau