Two days ago I got my first ever copy of GTA III for the PC that wasn't pirated. Yesterday, I modded one of the vehicles, but that got messed up, so I uninstalled the game and deleted all of the VirtualStore data to get rid of the broken files. Last night I reinstalled the game. Everything seems to be working right, but whenever I go on the Callahan Bridge to Staunton Island, I see this:

I don't think it's the fault of the actual disc, that thing is virtually spotless. What do I do?
If required, these are my system specs:
OS: Windows Vista Home Premium SV2
Processor: AMD Athlon 64 X2 Dual Core Processor, 2.10 GHz
RAM: 1.00 GB
Video Card: NVIDIA GeForce GT 240
System type: 32-bit