Cannot allocate memory / Couldn't realloc input buffer

[Don MacAskill]

After upgrading to 1.2.2 I'm sometimes seeing these messages when 
memcached is run with "-v":

malloc(): Cannot allocate memory
Can't listen for events on fd 3044
malloc(): Cannot allocate memory
Can't listen for events on fd 3044
malloc(): Cannot allocate memory
Can't listen for events on fd 3044
malloc(): Cannot allocate memory
Can't listen for events on fd 3044
malloc(): Cannot allocate memory
Can't listen for events on fd 3044
malloc(): Cannot allocate memory
Can't listen for events on fd 3044
malloc(): Cannot allocate memory
Can't listen for events on fd 3044
Couldn't realloc input buffer
Couldn't realloc input buffer
Couldn't realloc input buffer
Couldn't realloc input buffer
Couldn't realloc input buffer


There seems to be enough free RAM on the systems in question (500MB+). 
It could easily be related to something other than the upgrade (higher 
load for some reason, etc), I just haven't looked yet.

Before diving in, has anyone else seen anything similar?

FYI, these are RHEL4 boxes.  I haven't yet seen the same messages on our 
RHEL5 boxes, but have no idea if that's a real datapoint or not.

Thanks!

Don