Hi @vishu
While I agree with everyone, that you should update to 2.2, you may want to
consider to update at least to the latest available release of the 1.6 branch
which is 1.6.0p30.
Additionally, have you checked the value of VMallocChunk in /proc/meminfo on
the host in question? Maybe… the check is raising an alert for a reason… 
Nice article about “what is what” in /proc/meminfo:
RHEL KB: /proc/meminfo values and their meaning
Note: Yes, this is quite old, but as far as I know the information in this article, is still valid.
HTH,
Thomas