Comment # 40 on bug 917411 from macias -

I found another difference between my previous (working) installation of OS
13.2 and current (freezing) one. Right after new install I tried to disable
automounting for external USB drives, like pendrives. So I added such rule:

# more /etc/udev/rules.d/85-no-automount.rules
SUBSYSTEMS=="usb", ENV{UDISKS_AUTO}="0", ENV{UDISKS_IGNORE}:="1"

Another story is, this rule didn't prevent automounting, but I left it in hope
some extra argument might work.

Anyway, now I disabled that rule and we will see if indeed this was the reason.

As reminder -- freezes didn't occur (never) on attach/detach of USB drive, and
I don't have any USB drive permanently attached.