I've committed the attached patch as a potential fix for this problem.
What it does is, it fakes the pressing of the left shift key after it
unblanks the screen. Could you confirm whether this fixes your problem?
Cheers,
Bart
--- lid.sh (revision 4358)
+++ lid.sh (working copy)
@@ -41,6 +41,12 @@
su $user -c "xscreensaver-command -deactivate"
fi
su $user -c "xset dpms force on"
+
+ # Press LEFT SHIFT. On some laptops / in some configurations forcing
+ # the DPMS on is not enough, X needs to be convinced to unblank the
+ # screen. The left shift key is probably the most harmless key we
+ # could press. :-)
+ acpi_fakekey 42
fi
done
fi
