Keyboard and mouse freezes with F18

[Patrick O'Callaghan]

I'm having a problem with F18 (updated from F17 using fedup and
distro-sync). The system configuration is:

Intel i915 onboard chipset
Hardwired keyboard and mouse
Flatron W2243S monitor
F18 x86_64
xorg-x11-server-Xorg-1.13.1-4.fc18.x86_64
KDE 4.9.5-2.fc18.x86_64
qt-4.8.4-6.fc18.x86_64
Mesa 9.0.1-3.fc18.x86_64

The problem appears after a long period of inactivity (but only some of
the time). I have the screensaver turned off and power management set to
dim the monitor but not power it down. The screen is lit but keyboard
and mouse are unresponsive, including Ctrl-Alt-Fn combinations. The
system is not hung as I can SSH in and everything seems to be working,
but attempts to use systemctl start runlevel3.target (or ... 5.target)
have no effect. The only option appears to be rebooting.

Anyone else seen this?

poc