unix - Ping Latency

[gollum123]

Hello all,

0.8.6d ; FreeBSD 5.4

poller.php is called every 5 mn.
All graphs are working great except the Unix - Ping Latency one.
They are created but refreshed only if launch poller.php by hand very frequently.

it's not a right matter, since i call the poller from the root crontab
I attached a sample

thank you in advance,