Your map is unoptimized. The compiler freezes because of how Windows Vista/7 check if a program is not responding. VVIS is just taking an extremely long time to complete. You need to optimize your map.
From the looks of it, your map is extremely complicated, considering VBSP is taking longer than a few short seconds to complete. You will probably be spending a considerable amount of time optimizing your map.
But basically, it “crashes,” meaning that Windows believes it’s hit an infinite loop and isn’t working properly, when really, it’s just running a bunch of repetitive calculations. It’s still running, but it doesn’t report back to the compile window. The L4D2 SDK addresses this issue, the compiler for L4D2 isn’t a separate form, it’s a command line program and they’ve modified the way it works so it doesn’t appear to have crashed.