I have a similar problem although mine freezes for longer, like 5-10 seconds, but only once every 10 mins or so.
cpu/ram usage 60% and gpu only 25%.
Ran ccleaner then restarted pc now works fine. Seems was a memory issue, needed to clean itself out. load times much quicker now too.
serious?u very mean, how u define unimportant
i also got this problem , what helps a little bit is restarting game and blocking gold sellers
i have the same problem, it just happened today
also here randomly freeze 
too annoy
freezes became longer o_O
any fix for this? really annoying and can cause death
Just got freeze while fighting boss, I died :\
no solution for now? Freezes are getting worse…
So far lost two boss dungeon loot because of shitty 4 second long game freezes. I have a six core i7 with a 780. The problem is with their server or shitty optimization of the game.