To save memory host deletes models in video ram when you leave the tab and rebuilds it when you come back. This normally (means on all my computers and many others) works without problem. It is still not clear why a few users have that problem. Can you please tell in detail (os, graphic card, openGL driver version,..) what computer you use and if it is with all models or only bigger ones. Are there any messages in the log windows at the bottom (easy mode off, toggle log). I guess as soon as we know where/why it happens, we will be able to fix it.
