Gran Turismo 4 not working...

[Almy]

So, I found this emulator, went to my uncle's, borrowed his PS2 and Gran Turismo 4, dumped BIOS and started... All that I got was this:    
It wouldn't go any further...

Then I did ************** and ran it... It got me to main menu which was sometimes missing a few first letters from a word or only one letter.    

I managed to buy a car and go to my first race, but this was all I got...    

Then I tried to open the orig one and load game, but it said no save was found and I'm stuck... I can't open the orig DVD or the ISO image...
These are my graphics settings:    

My PC specs are:
AMD Athlon X2 2,66GHz
Radeon HD4650 512MB
3GB RAM DDRII
If you need anything else, just say and I'll write it...

EDIT: I also tried 4 or 5 different combination of settings and DX's... Didn't help either. My GPU is compatible with DX10 and lower.

[avih]

At the garbage screen, press the "Start" button on the pad, then Screen Settings, then set Brightness to 0.

[Almy]

It helped. But when the car arrives to the starting line and when I should take over the controls this happens...    

Got rid of that too somehow... Now I only need to speed it up.

Also, why can't I run the original disc, but I can run the ISO image from the Internet?