MSP 430 UART Rx problem

Hello,

I'm working with the msp430 uart to interface with another component. My Tx function works just fine, but when I try to recieve a string of characters, I only end up getting the last one. I think this is because the Rx flag is only triggering once (though I thought it would trigger each time the rx buffer filled), but it could be some other issue. Please help. My code is below.

/*
 * main.c
 */

#include "msp430.h"
#include "stdio.h"


// Transfers the given string over the UCSI UART port. Uses explicit length, instead
  // of looking for a null byte to terminate the string.
  void TXString(char* string, int length, char* check){
    int pointer;
    for( pointer = 0; pointer < length; pointer++)
    {
      UCA1TXBUF = string[pointer];
      check[pointer]=UCA1TXBUF;
      while (!(UCA1IFG & UCTXIFG));              // USCI_A0 TX buffer ready?
    }
  }

volatile int i=0;

void main(void) {
	
	WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT


	 char output[2];
	output[0]='r';
	 output[1]='\r';


	  P5DIR |= (0x0040);
	  P5DIR &= ~(0x0080);

	  P5SEL |= (0x0040);
	  P5SEL |= (0x0080);
	  // P5.6,7 = USCI_A1 TXD/RXD


	  UCA1CTL1 |= UCSWRST;                      // **Put state machine in reset**
	  UCA1CTL1 |= UCSSEL_2;						//Select 1MHz clock
	  UCA1BR0 = 27;                           // baud rate=38400 (User's guide)
	  UCA1MCTL |= UCBRS_2+UCBRF_0;              // Modulation UCBRSx=2, UCBRFx=0

	  UCA1CTL0 = 0;								//Does all of the below things
	 						 // Parity disabled
	 					 // 8-bit data length
	  						 // 1 Stop bit
	 				 //Asynchronous mode
	 
	 UCA1CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
	UCA1IE |= UCRXIE+UCTXIE;                  // Enable USCI_A1 RX interrupt, AND Enable USCI_A1 TX interrupt


	  char check[20];

	  __enable_interrupt();					//Enabling interrupts without entering low power mode


	  P1DIR |= 0x01;                        // Set P1.0 to output direction for test
	  for(;;){

		  volatile unsigned int i;            // volatile to prevent optimization

		  P1OUT ^= 0x01;                      // Toggle P1.0 using exclusive-OR

		  TXString(output, 2, check);
		  		  i = 100000000;                          // SW Delay
		  		      do i--;
		  		      while (i != 0);
	  }

}


#pragma vector=USCI_A1_VECTOR
__interrupt void USCI_A1_ISR(void)
{
	char check2[20];


  switch(__even_in_range(UCA1IV,4))
  {
  case 0:break;                             // Vector 0 - no interrupt
  case 2:                                   // Vector 2 - RXIFG
	puts("Received!");
	check2[i]=UCA1RXBUF;					//This might not do what I think it does
     i++;
    printf("Check2[0]: %c \n", check2[0]);
    printf("Check2[1]: %c \n", check2[1]);
    printf("Check2[2]: %c \n", check2[2]);
    printf("Check2[3]: %c \n", check2[3]);
    printf("Check2[4]: %c \n", check2[4]);
    printf("Check2[5]: %c \n", check2[5]);
    printf("Check2[6]: %c \n", check2[6]);
    printf("Check2[7]: %c \n", check2[7]);

    break;
  case 4:
	  puts("Transmitted!");
	  break;                             // Vector 4 - TXIFG
  default: break;
  }
}