Brushes disappearing in game

[trees]

I'm having a problem in seemingly any new .vmf I compile, that brushes keep disappearing and reappearing when moving around in the map. In other maps it affects just a few brushes, but this one sketch map is going totally nuts. I have no idea what's going on, this never happened before. There's no leak either, the map is inside a simple box.

Pics:

So far so good
http://imgur.com/a/IGtpV

Glitches appear when going over certain spots
http://imgur.com/a/wSPnc
http://imgur.com/a/WCw27

Any idea as to what's happening here, I'm stumped? Also there's the problem that Hammer keeps crashing frequently, even when doing tiny simple sketches like this. Is there any way to make it more stable?

Here's the .vmf
http://s000.tinyupload.com/index.php?file_id=01076637740363911181

 

[200]

Crashing is a usual Hammer thing. As for the textures - I'm not sure why this is happening, but I suggest moving all the complex geometry like that roof into func_details. You might not want to generate this.

I made the entire building from your vmf into func_detail and the problem is gone.


Sometimes you also might want to just re-create glitching objects if they are not too complex - it saves a lot of time rather then debugging your map for several hours. Because yes, if you mess with vertex tool or carve something, you may get a brush that looks completely fine but is actually crazy in game.

 

[trees]

Indeed turning the building into func_detail did the trick. Thank you so much!
I've never really taken advance of this feature since most of my maps never make it past pre-alpha 1, but I'll certainly start using it.