I have a similiar problem but heres what I get.
BTW, this is new since the last patch. Never ever happened before that.
Usually on my first sortie of the game. Whether in a tank or a plane, doesnt matter, My screen freezes for about 5 seconds. Sound continues. Can't do anything to get out of the freeze. Then it comes back, I can alt tab, or just stay in the game. If I stay in the game though, my video goes all wierd, like I can't see the world map, like there holes in everything, some trees show up, but I can see through mountains, and the ground is basically empty space. I turn my video settings to everything off. Then the world comes back looking like playdo. Then I readjust my video setting turning bumpmap on, and detailed water, and detailed ground. I never use shadows. Then the game continues on and I never have the problem again. I say that it usually happens my first sortie, but sometimes its the second. It ALWAS Happens though. 
Heres my DXDIAG
------------------
System Information
------------------
Time of this report: 5/16/2011, 07:40:44
       Machine name: FLOATSRIG
   Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_gdr.101209-1647)
           Language: English (Regional Setting: English)
System Manufacturer: Gigabyte Technology Co., Ltd.
       System Model: EP43T-UD3L
               BIOS: Award Modular BIOS v6.00PG
          Processor: Intel(R) Core(TM)2 Duo CPU     E8400  @ 3.00GHz (2 CPUs)
             Memory: 3582MB RAM
          Page File: 737MB used, 6761MB available
        Windows Dir: C:\WINDOWS
    DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
     DxDiag Version: 5.03.2600.5512 32bit Unicode
------------
DxDiag Notes
------------
  DirectX Files Tab: No problems found.
      Display Tab 1: The file nv4_disp.dll is not digitally signed, which means that it has not been tested by Microsoft's Windows Hardware Quality Labs (WHQL).  You may be able to get a WHQL logo'd driver from the hardware manufacturer.
        Sound Tab 1: No problems found.
          Music Tab: No problems found.
          Input Tab: No problems found.
        Network Tab: No problems found.
--------------------
DirectX Debug Levels
--------------------
Direct3D:    0/4 (n/a)
DirectDraw:  0/4 (retail)
DirectInput: 0/5 (n/a)
DirectMusic: 0/5 (n/a)
DirectPlay:  0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow:  0/6 (retail)
---------------
Display Devices
---------------
        Card name: NVIDIA GeForce 9800 GT  
     Manufacturer: NVIDIA
        Chip type: GeForce 9800 GT
         DAC type: Integrated RAMDAC
       Device Key: Enum\PCI\VEN_10DE&DEV_0614&SUBSYS_34AF1458&REV_A2
   Display Memory: 1024.0 MB
     Current Mode: 1280 x 1024 (32 bit) (85Hz)
          Monitor: Dell P1110
  Monitor Max Res: 1800,1440
      Driver Name: nv4_disp.dll
   Driver Version: 6.14.0011.9728 (English)
      DDI Version: 9 (or higher)
Driver Attributes: Final Retail
 Driver Date/Size: 3/23/2010 03:23:16, 6447872 bytes
      WHQL Logo'd: No
  WHQL Date Stamp: None
              VDD: n/a
         Mini VDD: nv4_mini.sys
    Mini VDD Date: 3/23/2010 03:23:16, 10274176 bytes
Device Identifier: {D7B71E3E-4554-11CF-E851-A41403C2CB35}
        Vendor ID: 0x10DE
        Device ID: 0x0614
        SubSys ID: 0x34AF1458
      Revision ID: 0x00A2
      Revision ID: 0x00A2
      Video Accel: ModeMPEG2_C ModeMPEG2_D 
 Deinterlace Caps: {6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) 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 
                   {6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(UYVY,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive 
                   {335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(UYVY,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalSt retch 
                   {6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(YV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive 
                   {335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalSt retch 
                   {6CB69578-7617-4637-91E5-1C02DB810285}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) 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 
         Registry: OK
     DDraw Status: Enabled
       D3D Status: Enabled
       AGP Status: Enabled
DDraw Test Result: Not run
 D3D7 Test Result: Not run
 D3D8 Test Result: Not run
 D3D9 Test Result: Not run
-------------
Sound Devices
-------------
            Description: Realtek HD Audio output
 Default Sound Playback: Yes
 Default Voice Playback: Yes
            Hardware ID: HDAUDIO\FUNC_01&VEN_10EC&DEV_0888&SUBSYS_1458A002&REV_1000
        Manufacturer ID: 1
             Product ID: 100
                   Type: WDM
            Driver Name: RtkHDAud.sys
         Driver Version: 5.10.0000.5874 (English)
      Driver Attributes: Final Retail
            WHQL Logo'd: Yes
          Date and Size: 6/25/2009 02:07:44, 5095936 bytes
            Other Files: 
        Driver Provider: Realtek Semiconductor Corp.
         HW Accel Level: Standard
              Cap Flags: 0xF5F
    Min/Max Sample Rate: 8000, 192000
Static/Strm HW Mix Bufs: 33, 32
 Static/Strm HW 3D Bufs: 33, 32
              HW Memory: 0
       Voice Management: No
 EAX(tm) 2.0 Listen/Src: No, No
   I3DL2(tm) Listen/Src: No, No
Sensaura(tm) ZoomFX(tm): No
               Registry: OK
      Sound Test Result: Not run
---------------------
Sound Capture Devices
---------------------
            Description: Realtek HD Audio Input
  Default Sound Capture: Yes
  Default Voice Capture: Yes
            Driver Name: RtkHDAud.sys
         Driver Version: 5.10.0000.5874 (English)
      Driver Attributes: Final Retail
          Date and Size: 6/25/2009 02:07:44, 5095936 bytes
              Cap Flags: 0x41
           Format Flags: 0xFFF
            Description: Realtek HD Digital input
  Default Sound Capture: No
  Default Voice Capture: No
            Driver Name: RtkHDAud.sys
         Driver Version: 5.10.0000.5874 (English)
      Driver Attributes: Final Retail
          Date and Size: 6/25/2009 02:07:44, 5095936 bytes
              Cap Flags: 0x41
           Format Flags: 0xFFF
-----------
DirectMusic
-----------
        DLS Path: C:\WINDOWS\SYSTEM32\drivers\GM.DLS
     DLS Version: 1.00.0016.0002
    Acceleration: n/a
           Ports: Microsoft Synthesizer, Software (Not Kernel Mode), Output, DLS, Internal, Default Port
                  Microsoft MIDI Mapper [Emulated], Hardware (Not Kernel Mode), Output, No DLS, Internal
                  Microsoft GS Wavetable SW Synth [Emulated], Hardware (Not Kernel Mode), Output, No DLS, Internal
        Registry: OK
     Test Result: Not run