Problem using timer interruptions

Hi. I'm having a problem with a very simple code. When I run it with te computer using Keil it works fine, but when I send it to the micro controller it doesn't work. I don't think it's the device that I'm using to send the program to the controller, because it works fine when i send a similar code in assembly language. The problem is when i use C. Here is the code:

#include <REGx52.H>

void seteo_inicial (void);

int main (void){
        seteo_inicial ();
        while (1){
                ACC=1;
        }
        return 1;
}

timer0_int () interrupt 1{
        TR0=0;
        TR1=0;
        TH0=0xfb;
        TL0=0x00;
        TL1=0x00;
        TH1=0xfd;
        P2=0xff;
        TR1=1;
        TR0=1;
}

timer1_int () interrupt 3{
        TR1=0;
        P2=0x00;
}

void seteo_inicial (void){
        P2=0x00;
        IP=0x22;
        TR0=0;
        TR1=0;
        IE=0xaa;
        TMOD=0x11;
        TH0=0xfb;
        TL0=0x00;
        TR0=1;
}

The port 2 should be changing its value from 0x00 to 0xff continuously, but this isn't the case, and i don't know why. Can someone help me with this?

Thanks
Tomas