You guys getting stuttering, what is the Vidmem being reported under the frame rate counter.  Not the used, that's incorrect at the moment, just the Vidmem.  Does that number correspond with the amount of memory shown in dxdiag?
yep shows correct 256 for me.
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System Information
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Time of this report: 7/29/2009, 11:59:30
       Machine name: MIKE-3LI8VJ5OAM
   Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_gdr.090206-1234)
           Language: English (Regional Setting: English)
System Manufacturer: System manufacturer
       System Model: System Product Name
               BIOS: Phoenix - Award BIOS v6.00PG
          Processor: AMD Athlon(tm) 64 Processor 4000+,  MMX,  3DNow, ~2.4GHz
             Memory: 2048MB RAM
          Page File: 429MB used, 5464MB 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
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Display Devices
---------------
        Card name: NVIDIA GeForce 7800 GTX 
     Manufacturer: NVIDIA
        Chip type: GeForce 7800 GTX
         DAC type: Integrated RAMDAC
       Device Key: Enum\PCI\VEN_10DE&DEV_0091&SUBSYS_00000000&REV_A1
   Display Memory: 256.0 MB
     Current Mode: 1920 x 1200 (32 bit) (60Hz)
          Monitor: LG W2452(Analog)
  Monitor Max Res: 1920,1200
      Driver Name: nv4_disp.dll
   Driver Version: 6.14.0011.8250 (English)
      DDI Version: 9 (or higher)
Driver Attributes: Final Retail
 Driver Date/Size: 3/27/2009 10:03:00, 6186880 bytes
      WHQL Logo'd: Yes
  WHQL Date Stamp: n/a
              VDD: n/a
         Mini VDD: nv4_mini.sys
    Mini VDD Date: 3/27/2009 10:03:00, 6280416 bytes
Device Identifier: {D7B71E3E-43D1-11CF-8A43-0B2000C2CB35}
        Vendor ID: 0x10DE
        Device ID: 0x0091
        SubSys ID: 0x00000000
      Revision ID: 0x00A1
      Revision ID: 0x00A1