This is the problems i had.
FPS drop at the green goo right before you get of the tram in the beginning.
bm_c1a4e green goo saw thing - fps drop
When the first Houndeye appears - fps drop.
3 head monster - fps drop.
Running from gargantuan/blowing the antenna, c2a5g - fps drop.
Game crashes after turning on the ventilator.
Random crash when Gordon is colliding with Headcrabs and/or other props.
Game crash in c2a5b walking through the pibes (Can’t load lump 53, allocation of 962657 bytes failed)
Smoke from helicopter looks wierd? - Dam bm_c2a5a
Game crash c2a5c, canyon when shooting down helicopter.
many red error messages in console (Physics queue not empty, error!..etc)
The FPS Drop may be a computer problem. But i have no other problems in other Source games.
min( when dropping): 30-40 you can feel the lagging/stutter when i drops
avg: 120
max: 300
OS: Windows 8 Pro RTM, 64 bit
MB: Rampage III extreme
CPU: i7-950 (NO OC)
RAM: Corsair 12GB (1600mhz)
GFX: GAINWARD 580 GTX 3GB
Harddrive: SSD 120GB
SCREEN RES: 1080p
Nice game 
EDIT: BTW settings on MAX 
added more errors.
hl2_4104_crash_2012_9_14T17_25_33C0.mdmp (110 KB)
hl2_4104_crash_2012_9_14T17_26_14C0.mdmp (111 KB)
hl2_4104_crash_2012_9_14T17_2_30C0.mdmp (98.5 KB)
hl2_4104_crash_2012_9_14T23_33_21C0.mdmp (104 KB)
hl2_4104_crash_2012_9_15T13_7_53C0.mdmp (104 KB)