[LightDM] lightdm-1.4.0 crashes periodically

[Grant]

lightdm-1.4.0 seems to crash periodically on Gentoo for both my wife
and I on separate but identical laptops.  The xfce4 desktop goes blank
and the lightdm screen appears.  The only thing I can find in the logs
is this in the kernel log but I don't think it's helpful:

grsec: denied resource overstep by requesting 4096 for RLIMIT_CORE
against limit 0 for /usr/bin/Xorg[X:2186] uid/euid:0/0 gid/egid:0/0,
parent /var/tmp/portage/x11-misc/lightdm-1.4.0/image/usr/sbin/lightdm[lightdm:2163]
uid/euid:0/0 gid/egid:0/0

How can I go about getting more information?

- Grant