I2C - speed issues - following TI's example code, I2C clock only runs at 370k rather than 400k

I'm working with the CC3200 on the LaunchPad, rev 3.2.

I've set up pins 1 and 2 for I2C following the code defined in the I2C example.

Running at "fast" speed, I only see the clock running at about 370K instead of 400.    Why is this?     I've attached a picture of the scope trace showing the behavior.   My slave device is expecting to run at 400K.    I see intermittent communication failure and I suspect that the problem is the slow master clock.  Yellow is the clock.  You can see on the right side of the screen that 1/deltaX = 370k.   I've verified that the Register controlling the timing (I2CMTPR) is set to 9 as specified in the Technical Reference Manual.

Please advise on how to fix this problem.

Code is here.   I'm using TI's library functions almost exclusively.

main ()

...

BoardInit();
    
 PinMuxConfig();
  //
  // Configuring UART
  //
  InitTerm();

  //I2C setup
  I2C_IF_Open(I2C_MASTER_MODE_FST);
  MAP_UtilsDelay(26666667);
 
  InitAccelerometer();  //I2C commands are Transmitted here after 1 second delay

...

}

PinMuxConfig has the following for I2C pin setup

    MAP_PRCMPeripheralClkEnable(PRCM_I2CA0, PRCM_RUN_MODE_CLK);
       // Configure PIN_01 for I2C0 I2C_SCL
       //
       MAP_PinTypeI2C(PIN_01, PIN_MODE_1);

       //
       // Configure PIN_02 for I2C0 I2C_SDA
       //
       MAP_PinTypeI2C(PIN_02, PIN_MODE_1);