When I moved from syslog to syslog-ng on my laptop running Fedora 7, I noticed a lot of these warnings in /var/log/messages:

Jul 10 09:29:34 speedy syslog-ng[2272]: Number of allowed concurrent connections exceeded; num='10', max='10'

Increasing the maximum number of connections for the Unix stream that reads /dev/log seemed to fixed this problem:

source s_sys {
    file ("/proc/kmsg" log_prefix("kernel: "));
    unix-stream ("/dev/log" <strong>max-connections(20)</strong>);
    internal();
    # udp(ip(0.0.0.0) port(514));
};