"Resending StartCore message to master" error

Every once in a while we get the following errors in FIMS 4.5 edge log file and stream stop to work for the affected vhost until we restart FMS:

2014-11-07 19:40:59 28122 (i)2581537 Resending StartCore message to master (vhost: vhostnamehere, app: , inst: , tag: _2).

Server is an Intel Xeon E5405 running CentOS 5.1 with 16 GB RAM.

The error does not cause other vhosts to work just the affected one. Although the error seems to occur ar random times and not when server is under heavy load, here is a snapshot of the memory usage while the error is being reported and after FMS is restarted fixing the problem:

             total       used       free     shared    buffers     cached

Mem:      16434952   14240400    2194552          0     135128    7211612

-/+ buffers/cache:    6893660    9541292

Swap:      6088624        180    6088444

AFTER FMS restarted fixing issue:

             total       used       free     shared    buffers     cached

Mem:      16434952   10836248    5598704          0     182740    7716368

-/+ buffers/cache:    2937140   13497812

Swap:      6088624        180    6088444

Could it be an insufficient memory issue? I have noticed this error at least on one occasion when attempts were made to play a high bitrate (3000 kbps) VOD.

What could be causing this seemingly random issue and are there any tweaks that can be made to FMS to help prevent it? Or do we need to throw in more RAM? 16 GB seems like plenty enough.