Normal 1.6.4 plays fine, snapshot worked until the previous of this one. Downloaded the latest above and problem still persisted. Was able to play for about a few minutes and then screen drawing became a problem. The problem persisted with new levels created. Attached Screenshots of the problem. The speed of the game got very slow at the same time. Sometimes it draws fine. Loaded it again to take a screen shot and it worked this time. When it happens again I will attach a screen shot. Lines are drawn but the textures appear not to be drawn. (See through world) with what appears to be some shading applied. (water is green). I loaded a non default texture and it worked for some time and then same issue came about after a few minutes. Leaving on the Game menu (hit escape during game play) extends the time (no redrawing). It occured after a few minutes again (although now happends quicker once you get app into this state). ATI video card (4800 series if it could be a driver issue, but like I said earlier versions worked). Tried tweaking chunks drawn to make sure it was not a memory issue, no graphic settings fixed it. I noticed in the attached screenshot glass was drawn (blue and white boxes), so textures partially drew this time, where previously only the borders were drawn. (no textures at all). Seems like somewhere in the drawing routine it drops out without finishing.