I was playing around offline and i notice the new shadows on other option. After enabling this, I found that my frame rate would drop from 100+ (Benchmark test with Vsync off) all the way down to 1, sometimes maybe even reseting my graphics settings.
I can record with fraps what happens if you need me to.
System info below, it's pretty beast for AH2.
------------------
System Information
------------------
Time of this report: 4/25/2010, 00:36:13
       Machine name: ********
   Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7600) (7600.win7_gdr.100226-1909)
           Language: English (Regional Setting: English)
System Manufacturer: System manufacturer
       System Model: System Product Name
               BIOS: BIOS Date: 07/23/09 18:29:19 Ver: 08.00.15
          Processor: Intel(R) Core(TM) i7 CPU         920  @ 2.67GHz (8 CPUs), ~2.7GHz
             Memory: 6144MB RAM
Available OS Memory: 6136MB RAM
          Page File: 3440MB used, 8828MB available
        Windows Dir: C:\Windows
    DirectX Version: DirectX 11
DX Setup Parameters: Not found
   User DPI Setting: Using System DPI
 System DPI Setting: 96 DPI (100 percent)
    DWM DPI Scaling: Disabled
     DxDiag Version: 6.01.7600.16385 32bit Unicode
Display Devices
---------------
          Card name: ATI Radeon HD 5800 Series 
       Manufacturer: ATI Technologies Inc.
          Chip type: ATI display adapter (0x6899)
           DAC type: Internal DAC(400MHz)
         Device Key: Enum\PCI\VEN_1002&DEV_6899&SUBSYS_0B001002&REV_00
     Display Memory: 3819 MB
   Dedicated Memory: 1012 MB
      Shared Memory: 2807 MB
       Current Mode: 1680 x 1050 (32 bit) (60Hz)
       Monitor Name: Generic PnP Monitor
      Monitor Model: SyncMaster
         Monitor Id: SAM0302
        Native Mode: 1680 x 1050(p) (59.883Hz)
        Output Type: DVI
        Driver Name: atiu9p64.dll,aticfx64.dll,aticfx64.dll,atiu9pag,aticfx32,aticfx32,atiumd64.dll,atidxx64.dll,atidxx64.dll,atiumdag,atidxx32,atidxx32,atiumdva,atiumd6a.cap,atitmm64.dll
Driver File Version: 8.14.0001.6099 (English)
     Driver Version: 8.712.3.0
        DDI Version: 10.1
       Driver Model: WDDM 1.1
  Driver Attributes: Final Retail
   Driver Date/Size: 3/14/2010 09:16:46, 28160 bytes
        WHQL Logo'd: n/a
    WHQL Date Stamp: n/a
  Device Identifier: {D7B71EE2-2BD9-11CF-6164-012BA1C2C535}
          Vendor ID: 0x1002
          Device ID: 0x6899
          SubSys ID: 0x0B001002
        Revision ID: 0x0000
 Driver Strong Name: oem9.inf:ATI.Mfg.NTamd64.6.1:ati2mtag_Evergreen:8.712.3.0:pci\ven_1002&dev_6899
     Rank Of Driver: 00E62001
        Video Accel: ModeMPEG2_A ModeMPEG2_C 
   Deinterlace Caps: {6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive 
                     {335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalSt retch 
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY 
                     {6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive 
                     {335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalSt retch 
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY 
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YV12,0x32315659) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
                     {3C5323C1-6FB7-44F5-9081-056BF2EE449D}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive 
                     {552C0DAD-CCBC-420B-83C8-74943CF9F1A6}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive 
                     {6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive 
                     {335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalSt retch 
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY 
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC1,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC2,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC3,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC4,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(S340,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
                     {5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(S342,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
       D3D9 Overlay: Not Supported
            DXVA-HD: Not Supported
       DDraw Status: Enabled
         D3D Status: Enabled
         AGP Status: Enabled