Why Are My Project Assets Constantly Re-Importing?

I have a large project that is constantly re-importing its assets. I'm not sure of the exact cause but it seems to be at least loosely related to loading levels additively. However, the re-importing can occur at any time. For example I may load a level with the game running and the imports progress bar will pop up. But I could be in the editor, without the game running and click on a scrollbar or other innocuous UI and the assets will re-import again. This takes several minutes each time and happens at seemingly random intervals but can occur up to several times an hour which is quite annoying. I'm wondering if there is a bug in the way the assets are cached or the interaction with the cache when using additive scenes. I had seen the exact same thing happen in a completely unrelated project after using additive loading. I want to stress that this doesn't appear to be a coding isue. It happens even when the game is not running in the editor. I don't believe its ever happened in a built version of the game.

Has anyone else experienced this and know a way around it? For now I've disabled autorefresh on the project but this is not a great solution as I have to remember to manually refresh the project all the time.


Does anyone know if Unity 3.0 resolves this issue? We are just going through the upgrade process and my colleague has not experience the re-import issue since upgrading. Is this officially resolved in this release?

There's a thread here about this problem and so far there is not really any answer that works and stays working.

The only thing I've found that -somewhat- works is enabling "External Version Control" and turning off "autorefresh". Then I just hit CTRL+R to load scripts. It seems to make the problem happen a little less often, but it doesn't solve it completely.