Failed tcp connection attempts after upgrading to 1.5

[Chris Gilmore]

I've recently upgraded from haproxy 1.4.22 to 1.5.2.
Ever since then, I have noticed that I am now getting failed tcp connection
attempts on the remote servers.  The rate is equal to the 'inter' value
(for example, 1 failed connection attempt every 2 seconds).  Should I be
concerned about this?  Other than that, everything appears to be working
properly.

The haproxy configuration sets up a tcp health check for a set of mysql
servers (note: I am not using the mysql-check option).
Below is my haproxy.cfg

global
    log         127.0.0.1 local2

    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

    stats socket /var/lib/haproxy/stats

defaults
    mode                    tcp
    log                     global
    option                  dontlognull
    option                  redispatch
    retries                 3
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout check           10s
    maxconn                 3000

listen mysql
    bind :3306
    mode tcp
    balance leastconn
    server first 10.###.###.###:3306 check
    server second 10.###.###.###:3306 check
    server firstbackup 10.###.###.###:3306 check backup
    server secondbackup 10.###.###.###:3306 check backup