[Observium] Observium constantly device down and up by ping

Hi Guys,

Our observium (latest) 0.14.8.5749 has for some time been showing devices up and down in the event log, graphs missing chucks of information as well.

As an example, here is the memory usage on one ubnt box, but, its the same for others too (network / memory ) http://gyazo.com/18db347a5d49e557c082f343b8e96ea5

Here is the copy of the event log for the device : http://gyazo.com/4324c896e6cc268a8869d17c80964340

I can't seem to narrow it down.

The machine is running Ubuntu 12.04.5 LTS and as mentioned above, latest Observium.

Any ideas where to poke ? Its not a single device, its multiple devices. The only thing so far I have not swapped out is the server observium sits on.