De-synced enemies and player-characters

From time to time I have warping enemies and sometimes even I get glitched and moved to a position where I was certainly not standing. I'm not sure what's causing this, but it is very common a very common issue for me.

Also, I sometimes get hit by melee monsters who are in a completely different room than me.

Anyone else suffering from these problems?

Also, specs:
D-Link DWA-140 connected to a ASUS RT-N56U on a 30/5-connection.
AMD Phenom X4 965 running at default 3.4 GHz
12 GB RAM
ASUS M4A79T Deluxe790FX AM3 ATX
Win 8 64-bit

I do not have any lag-issues in any other games.

This issue has still not been resolved and other people are experiencing this as well.

In addition: I've also been hit by projectiles which I saw that my enemies did not launch and which were not shown while traveling towards me.