I have the same problem, and the same graphics card. I recently upgraded my processor and motherboard, and this is the second game I've tried to play on it (the first, Civilization 4, had similar issues). Maybe it's a compatibility problem?
I've got a eVGA GeForce 6600 GTS and an Asus A8V-MX motherboard. My debug info is below. Thanks!
Debug Message: Version v1.5 last updated on: Thu Jan 11 13:39:19 2007
Debug Message: Can't find TGN or GalCiv2 serial number.
Debug Message: GalCiv2 is activated.
Debug Message: Checking DX Version.
Debug Message: *********DXDiag info follows.*********
System Info
Time: 2/21/2007, 19:12:15
DirectX Version: DirectX 9.0c (4.09.0000.0904)
Machine Name: KATANA
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_gdr.050301-1519)
Languages: English (Regional Setting: English)
System Manufacturer: System manufacturer
System Model: System Product Name
BIOS: BIOS Date: 11/09/05 11:45:49 Ver: 08.00.12
Processor: AMD Athlon(tm) 64 FX-55 Processor, MMX, 3DNow, ~2.6GHz
Physical Memory: 1024MB RAM
Page File: 381MB used, 2078MB available
Windows Dir: C:\WINDOWS
Display Info
Display device 1:
Device Name: \\.\DISPLAY1
Card Name: NVIDIA GeForce 6600 GT
Manufacturer: NVIDIA
Chip Type: GeForce 6600 GT
DAC Type: Integrated RAMDAC
Key Device: Enum\PCI\VEN_10DE&DEV_00F1&SUBSYS_A3503842&REV_A2
Display Memory: 128.0 MB
Current Display Mode: 1600 x 1200 (32 bit) (75Hz)
Monitor Name: Samsung SyncMaster 900NF(T)
Monitor Max Resolution: 2048,1536
Driver Name: nv4_disp.dll
Driver Version: 6.14.0010.9147
Driver Date: 8/11/2006 20:42:52
DirectX Acceleration Enabled: Yes
Sound info
Sound device 1:
Description: Realtek AC97 Audio
Default Sound Playback: Yes
Default Voice Playback: Yes
Hardware ID: PCI\VEN_1106&DEV_3059&SUBSYS_81B91043&REV_70
Manufacturer ID: 1
Product ID: 100
Driver Name: ALCXWDM.SYS
Provider: Realtek Semiconductor Corp.
Driver Version: 5.10.0000.5890
Driver Date: 7/26/2005 11:03:22
Type: WDM
Other Drivers:
Acceleration Level: 3
Cap Flags: 0
Min/Max Sample Rate: 0, 0
Debug Message: *********END dxdiag info.*********
Debug Message: Entering WinMain
Debug Message: ******* Starting Game Shell *******
Debug Message: Going Fullscreen
Debug Message: Preparing to change display settings.
Debug Message: Using multilsample setting: D3DMULTISAMPLE_4_SAMPLES
Debug Message: Game Resolution: 1024 x 768
Debug Message: Running fullscreen.
Debug Message: HAL (hw vp): NVIDIA GeForce 6600 GT
Debug Message: D3DPRESENT_INTERVAL_DEFAULT
Debug Message: Refresh rate: 75
Debug Message: Bit Depth: 32 bit.
Debug Message: *********Checking D3DDevice Caps***********************
Debug Message: A full-color cursor is supported in hardware at high resolution modes.
Debug Message: RGB in format 6:6:6, Masks reported as ff0000:ff00:ff
Debug Message: Now Fullscreen
Debug Message: Shell initialization complete
Debug Message: ***** Initializing Game *****
Debug Message: Timer Frequency is 0 369e99
Debug Message: Initializing sound card.
Debug Message: initailizing bink
Debug Message: Create setup screens.
Debug Message: Clear galaxy settings.
Debug Message: Clear influence.
Debug Message: Clear up laws.
Debug Message: Clear first time events.
Debug Message: Clear wonders and trade goods.
Debug Message: Clear sector mapper.
Debug Message: * Collectors Edition *
Debug Message: Set mouse.
Debug Message: Set update timer.
Debug Message: Clear data definitions.
Debug Message: No files found matching mask C:\Documents and Settings\Shane Ryoo\My Documents\My Games\GalCiv2\ships\*.xml
Debug Message: No files found matching mask C:\Documents and Settings\Shane Ryoo\My Documents\My Games\GalCiv2\ships\*.shipcfg
Debug Message: Reading Star Names
Debug Message: Reading Star Names... Done
Debug Message: WM_CLOSE message received.
Debug Message: GameUninitialize start
Debug Message: Killing Galaxy
Debug Message: Killing threads.
Debug Message: Kiling civs.
Debug Message: Killing ships.
Debug Message: Killing rallypoints.
Debug Message: Killing misc objects.
Debug Message: Killing stars.
Debug Message: Killing anomalies.
Debug Message: Killing space resources.
Debug Message: Killing colonies and planets.
Debug Message: killing scenario.
Debug Message: Clearing Turn Event Log
Debug Message: Clear galaxy settings.
Debug Message: Clear influence.
Debug Message: Clear up laws.
Debug Message: Clear first time events.
Debug Message: Clear wonders and trade goods.
Debug Message: Clear sector mapper.
Debug Message: Clear data definitions.
Debug Message: Killing Galaxy: Completed
Debug Message: Shutting down sound system.
Debug Message: Clearing sound and music handles.
Debug Message: GameUninitialize end
Debug Message: Device not cleared. 1 counts left.
Debug Message: D3D not cleared. 1 counts left.
Debug Message: Destroying Window.
Debug Message: Main Shell terminating normally