i found a small temporary fix in game for these graphics problems.
When u start to see the odd white/coloured box inplace of terrain, names, skills, animations etc. Press F10 and click options. From there on the left click graphics, tick the box "use in window mode" and press save settings. Press F10, move around abit, might be laggy for some. Now go back into graphics options and undo that change.
For me it removed all those blotches, doesn't prevent it from coming back again thou. But enables you to stay playing longer without the game crashing around you.
In meantime do as SavageRaider says and send Customer Support Ticket to K2 about the problem asking for a new patch with the fix.
K2 fixed problem updating Xtrap