Same here, after a few minutes frames braking down and finally freezes. Alt+F4 or Esc dosn't working. I have to shut down the game by the Task Manager. It occur on all servers. I noticed in the Task Manager that the used working memory was very high like 700 MB to 1,3 GB. Occuring after last patch on 2014-02-07 version: 0.34.115106
I have 16 GB RAM
Win 7 64 bit
ATI Radeon HD 5800 Pro