Frame-rate Issues

[shof]

I too noticed alot of shuttering and lag when i play the game and drive on the bay bridge. My specs:

Motherboard:
CPU Type QuadCore AMD Phenom II X4 925, 2800 MHz (14 x 200)
Motherboard Name Asus M3A78 (3 PCI, 2 PCI-E x1, 1 PCI-E x16, 4 DDR2 DIMM, Audio, Gigabit LAN)
Motherboard Chipset AMD 770, AMD K10
System Memory 6144 MB (DDR2-800 DDR2 SDRAM)
DIMM1: Corsair XMS2 CM2X2048-6400C5 2 GB DDR2-800 DDR2 SDRAM (5-5-5-18 @ 400 MHz) (4-4-4-13 @ 270 MHz)
DIMM2: Corsair XMS2 CM2X2048-6400C5 2 GB DDR2-800 DDR2 SDRAM (5-5-5-18 @ 400 MHz) (4-4-4-13 @ 270 MHz)
DIMM3: Corsair XMS2 CM2X2048-6400C5 2 GB DDR2-800 DDR2 SDRAM (5-5-5-18 @ 400 MHz) (4-4-4-13 @ 270 MHz)
BIOS Type AMI (09/22/09)

Display:
Video Adapter NVIDIA GeForce GTS 250 (1024 MB)
3D Accelerator nVIDIA GeForce GTS 250
Monitor Dell 1707FP (Digital) [17" LCD] (CC35272122VC)
Monitor Generic PnP Monitor [NoDB] (000000000)

Multimedia:
Audio Adapter Creative SB X-Fi XtremeGamer Sound Card

Storage:
IDE Controller Standard Dual Channel PCI IDE Controller
Disk Drive ST3320620AS ATA Device (320 GB, 7200 RPM, SATA-II)
Disk Drive WDC WD3200AAKS-00B3A0 ATA Device (298 GB, IDE)
Optical Drive HL-DT-ST DVD-RAM GH22NS30 ATA Device (DVD+R9:16x, DVD-R9:12x, DVD+RW:22x/8x, DVD-RW:22x/6x, DVD-RAM:12x, DVD-ROM:16x, CD:48x/32x/48x DVD+RW/DVD-RW/DVD-RAM)
SMART Hard Disks Status OK

Game plays very smooth on my system with no lags or anything like that, until i enter the bay bridge area. does anyone know why?