I've had this one too. Incidentally the helicopter blades also turn black. Not sure what the trigger is but my specs are:
DirectX Version: DirectX 9.0c (4.09.0000.0904)
Machine Name: AREA51
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: alienware
System Model: alienware
BIOS: Phoenix - Award BIOS v6.00PG
Processor: Intel(R) Pentium(R) 4 CPU 3.20GHz (2 CPUs)
Physical Memory: 1024MB RAM
Page File: 275MB used, 2184MB available
Windows Dir: C:\WINDOWS
Display Info
Display device 1:
Device Name: \\.\DISPLAY1
Card Name: NVIDIA GeForce 6800 Series GPU
Manufacturer: NVIDIA
Chip Type: GeForce 6800 GT
DAC Type: Integrated RAMDAC
Key Device: Enum\PCI\VEN_10DE&DEV_00F9&SUBSYS_C3763842&REV_A2
Display Memory: 256.0 MB
Current Display Mode: 1024 x 768 (32 bit) (70Hz)
Monitor Name: SyncMaster 910V/910M/913V/915V
Monitor Max Resolution: 1280,1024
Driver Name: nv4_disp.dll
Driver Version: 6.14.0010.9133
Driver Date: 6/23/2006 16:49:00