Linux – Cinnamon randomly loses theming

From time to time (quite randomly), Nemo on my Linux Mint 14 Cinnamon starts looking like this

When usually it looks like this:

Restarting Cinnamon (Alt+F2, r, Enter) doesn't help, I need to log out, and then log on.

Can someone tell me,

• (I guess, that something with X Window System had crashed. dmesg doesn't show anything.) how to diagnose, what really happened? (update: it seems it is gnome-settings-daemon crash)
• how to restore the normal theme without logging off (which requires closing all programs)?
• how to minimize frequency of such things?

Suspicious entries in xsession-errors.lob

[0x7f9590006068] main input error: ES_OUT_SET_(GROUP_)PCR  is called too late (pts_delay increased to 300 ms)
[0x7f9590006068] main input error: ES_OUT_RESET_PCR called
[0x7f9590006068] main input error: ES_OUT_SET_(GROUP_)PCR  is called too late (pts_delay increased to 1108 ms)
[0x7f9590006068] main input error: ES_OUT_RESET_PCR called

(…)

[h264 @ 0x7f95790fc160] Missing reference picture
[h264 @ 0x7f95790fc160] decode_slice_header error
[h264 @ 0x7f95790fc160] mmco: unref short failure
[h264 @ 0x7f95790fc160] concealing 1620 DC, 1620 AC, 1620 MV errors
[h264 @ 0x7f95790fc160] Missing reference picture
[h264 @ 0x7f95790fc160] Missing reference picture
[h264 @ 0x7f95790fc160] Missing reference picture

(…)

No such schema 'com.canonical.unity-greeter'

Suspicious entries in syslog:

Jun 13 01:03:45 adam-N56VZ kernel: [49764.694213] gnome-settings-[4198]: segfault at 188b2 ip 00007f2e46acf0a6 sp 00007fff8acb45d0 error 4 in libgdk-3.so.0.600.0[7f2e46a8c000+7c000]
Jun 13 01:03:52 adam-N56VZ gnome-session[4098]: WARNING: Application 'gnome-settings-daemon.desktop' killed by signal 11

(…)

Jun 13 01:40:59 adam-N56VZ laptop-mode: Warning: Configuration file /etc/laptop-mode/conf.d/board-specific/*.conf is not readable, skipping.

Update:

It seems, that the this behavior can be reproduced by killing gnome-settings-daemon. The question remains on how to restore it? Simply running it as user or root doesn't change anything, even with restarting cinnamon (Alt+F2, r, Enter).

And the hardest question: how to prevent it from happening? Since it is a crash I guess I'll need to follow the procedure with filing bug report. But who's fault it is? Gnome's or Cinnamon's? Or maybe some other component is at fault here?