Bad luck, it's still there.
Seems to occur within the first five minutes.
So I cleared the log, restarted ETS2 and quit straight after the first freeze.
Here is the last part of the log, if anyone can decipher it.
00:01:59.303 : [hashfs] dlc_christmas.scs: Unmounted.
00:01:59.303 : [hashfs]...