c8051 and freescale mmma7660 i2c protocol

[tretra]

I'm trying to interface the freescale mma7660 accelerometer with an 8051 processor (c8051f020 silicon labs).
I get some problems while I communicate with the smbus:
I receive acks from the accelerometer, but the data I get is always 0.
This is my initialization code (for the accelerometer):

 SMB_DATA_IN[0] = 0x07; //stand by mode
 SMB_DATA_IN[1] = 0x00; 
 SMB_Write();           //write data on the smbus
 delay1ms(100);
 
 SMB_DATA_IN[0] = 0x06; //auto interrupt
 SMB_DATA_IN[1] = 0x10;
 SMB_Write();
 delay1ms(100);
 
 SMB_DATA_IN[0] = 0x08; //auto wake up
 SMB_DATA_IN[1] = 0x00;
 SMB_Write();
 delay1ms(100);
 
 SMB_DATA_IN[0] = 0x07; //active mode
 SMB_DATA_IN[1] = 0x01;
 SMB_Write();
 delay1ms(100);

And this is my read function:

void readData() {
 SMB_DATA_IN[0] = 0x00;//X value
 SMB_Write();
 delay1ms(100);
 
 SMB_Read();  //reads data and put everything in an array
}

I'm quite sure my smbus initialization is correct because I use the i2c protocol with other components without getting any problem.
This is the datasheet

Did I do something wrong? Any help would be greatly appreciated
Thanks