"could not receive data from client" && "incomplete startup packet"

I'm experiencing what appears to be an intermittent db connection problem of some sort (although I may be wrong about that).  I have a v9.3.0 PG DB on a linux box as the DB server.  The client is a virtual machine (also linux) running the same version...

My app is a perl script that I wrote using DBI and the PG DBD.    Looks like these are the versions...

I put print statements around the DB connection code to get a sense of what's happening there.  Sometimes it connects right away, sometimes there's a delay of a few seconds, sometimes it times out with an error.  If it does connect, sometimes it appears the connection will be dropped.  Where in the code it is dropped can vary.  It's not malformed sql code or anything like that.   The  error trapping (printing $dbh->err() ) returns nothing.  (I tested this code by giving it a malconstructed query using a different script and it gives me plenty !).  So I think the error trapping code is OK

I shut down and restarted the DB instance.  No difference.  

The DB log file back on the server side is replete with...

 "could not receive data from client: Connection reset by peer " 

followed by 

"incomplete startup package"

messages....

If it makes a difference, this problem seemed to begin when I created a second DB on the instance.  

I don't seem to have a problem connecting to the DB from the client side using good-ole psql.  It's always fast and stays 

The last clue I can think of is if the initial DB connection times out, a quick re-invocation of the script connects immediately (as if the first primed it in some way).  

Again, the client is a virtual machine, but the server is on metal.  

Any help would be appreciated!

Thanks