Strange blurring effect/frame rates

[baker_uk87]

System spec:

 

XP Pro no service packs

athlon 2600

1gb ddr333 ram

radeon 9800pro latest drivers

 

run GTA on:

1024 res, high FX, frame limiter on (WHAT IS FRAME LIMITER?).

 

The following effect happens: in day time, there is a kind of blurring happening like when your driving on the motorway and its a hot day, the kind of heat blurring your get, but also the FPS drop as well, not quite sure what could be causing this as the game can run at the high res/setting etc normally. But this weird effects happens...

 

Any ideas?

 

[jools1980]

I think that blurring is intentional: you can see that on tarmac any summer day over here (even if not driving), and in many other hot places.