I2CON = 0x44;// configure I2C interface

interrupt service routine...

switch(status)
  {
    case 0x08:	// Start condition Xmitted
    case 0x10:	// Repeat Start condition Xmitted
      I2DAT = mslaveaddress;
      STA = 0;
      STO = 0;
      SI = 0;    // does not work
      /*******OR******/
      I2CON &= 0x44;	// STA = STO = SI = 0; does not work
      mbytenum = 0;
      break;
      :
      :
      // All other status codes