Opening a shader takes a very long time

Hi, I noticed that after a couple hours intensively working with SF in Unity, a shader that used to take 25s to open right after I launched Unity can take up to 1m30s just to load.

It would probably end up taking even longer but that's when I got bored waiting (Unity is frozen while shaders load) and restarted Unity. This isn't a fluke by the way; I noticed this behavior always happen.

(I have a very fast CPU, graphics card, 16g of RAM and I'm on Windows 8 )