spurious byte transmitted when enabling USCI UART

Hi,

When I enable the uart I see a byte that I have not written to UCA1TXBUF appear on the hyperterminal screen.

It appears to happen just after:

UCA1CTL1 |= UCSWRST;

This is using a 5437 device.

I can avoid this by not setting P5SEL to uart until after I have pulled the USCI out of reset.

I also appear to have to add a delay before I begin transmitting in order to avoid errors.

If I add these modifications then I can transmit without issues

Is this behaviour expected? Not sure if it is something wrong with the USB->serial dongle that I have.

   UCA1CTL1 |= UCSWRST;                      // **Put state machine in reset**
   UCA1CTL1 |= UCSSEL_2;                     // SMCLK
   UCA1BR0 = (uint8_t)prescale;               // set prescaler
   UCA1BR1 = (uint8_t)(prescale>>8);
   UCA1MCTL |= UCBRS_7 + UCBRF_0;            // Modulation
   UCA1CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**                              
   //we seem to require this delay, still no idea why..
   __delay_cycles(1000);
   P5SEL = (BIT6 | BIT7);                    //Enable output pins after reset to avoid spurious transmit

Thanks,

Alistair