Interrupt will not fire

I have copied from code from the CSL_GPT example and compiled it into a test program of my own. I can't figure out why this interrupt never fires. Could someone look through this code and tell me what I'm doing wrong? I have confirmed that the GPT initalizes and begins its countdown, and resets afterwards.

/*GPT Test by Timothy Sapio 7-24-11
 * This program is for testing the various functionings of the General Purpose Timer module present in the TI 5505 Microcontroller.
 * It also demonstrates functioning of the timer by flashing the LED on and off.
 * */

#include "csl_gpt.h"
#include "csl_intc.h"
#include <csl_general.h>
#include "usbstk5505.h"
#include "led_test.h"

#define CSL_PLL_CLOCKIN    (32768u)

CSL_Handle    hGpt;
CSL_Status       status;
CSL_Config       hwConfig;
CSL_GptObj      gptObj;
Uint32    sysClk;

extern void VECSTART(void);
volatile Uint16    hitIsr = 0;

Uint32 getSysClk(void)
{
    Bool      pllRDBypass;
    Bool      pllOutDiv;
    Uint32    sysClk;
    Uint16    pllVP;
    Uint16    pllVS;
    Uint16    pllRD;
    Uint16    pllVO;

    pllVP = CSL_FEXT(CSL_SYSCTRL_REGS->CGCR1, SYS_CGCR1_VP);
    pllVS = CSL_FEXT(CSL_SYSCTRL_REGS->CGCR1, SYS_CGCR1_VS);

    pllRD = CSL_FEXT(CSL_SYSCTRL_REGS->CGICR, SYS_CGICR_RDRATIO);
    pllVO = CSL_FEXT(CSL_SYSCTRL_REGS->CGOCR, SYS_CGOCR_OD);

    pllRDBypass = CSL_FEXT(CSL_SYSCTRL_REGS->CGICR, SYS_CGICR_RDBYPASS);
    pllOutDiv   = CSL_FEXT(CSL_SYSCTRL_REGS->CGOCR, SYS_CGOCR_OUTDIVEN);

    sysClk = CSL_PLL_CLOCKIN;

    if (0 == pllRDBypass)
    {
        sysClk = sysClk/(pllRD + 4);
    }

    sysClk = (sysClk * ((pllVP << 2) + pllVS + 4));

    if (1 == pllOutDiv)
    {
        sysClk = sysClk/(pllVO + 1);
    }

    /* Return the value of system clock in KHz */
    return(sysClk/1000);
}


/**
 *  \brief  GPT Interrupt Service Routine
 *
 *  \param  none
 *
 *  \return none
 */
interrupt void gpt0Isr(void)
{
    hitIsr = TRUE;
    IRQ_clear(TINT_EVENT);
    /* Clear Timer Interrupt Aggregation Flag Register (TIAFR) */
    CSL_SYSCTRL_REGS->TIAFR = 0x01;
    toggleLED();
}

void main(void)
{
    USBSTK5505_init( );
    IRQ_setVecs((Uint32)(&VECSTART));
    IRQ_plug(TINT_EVENT, &gpt0Isr);
    IRQ_enable(TINT_EVENT);
    IRQ_globalEnable();
    hGpt = GPT_open(GPT_0, &gptObj, &status);
   
    sysClk = getSysClk();
   
    hwConfig.autoLoad      = GPT_AUTO_ENABLE;
    hwConfig.ctrlTim      = GPT_TIMER_ENABLE;
    hwConfig.preScaleDiv = GPT_PRE_SC_DIV_1;
    hwConfig.prdLow      = (sysClk)*10;
    hwConfig.prdHigh      = 0x0000;
   
    status =  GPT_config(hGpt, &hwConfig);
    //status = GPT_reset(hGpt);
    status = GPT_start(hGpt);
   
   
    while(1);
}