8051 timer inconsistant

Hi,

I have timer2 running on an interrupt and 99% of the time it works correctly, but sometimes the timer doesn't start or at least it doesn't enter this forever loop, Please could anyone give me any suggestions?

This is my interrupt:

void timer2_ISR (void) interrupt 5 {
		
		timer2Count++;
		if (timer2Count >
 50) {
			
			if (speedSensorCount < MIN_SPEED_DISC_TIMER) {
			        // stop timer2
			        TR2 = 0;
                                
                                // turn motors off
                                FMOTOR = 1;
	                        BMOTOR = 1;
	                        GREENLED = 0;
	                        REDLED = 0;
	
                                // loop forever
                         	for(;;) {
		                        beep();
		                        delayApplication(30);
		                        REDLED = !REDLED;
		                        GREENLED = !GREENLED;
	                         } 
			} else {
				timer2Count = 0;
			}
			
			
		}
		
		TF2 = 0;            /* Clear the interrupt request */
		
}

The problem is probably in the rest of the code,
most likely in how speedSensorCount is set.

I would not put

// loop forever
                         	for(;;)
                                {
		                        beep();
		                        delayApplication(30);
		                        REDLED = !REDLED;
		                        GREENLED = !GREENLED;
	                         } 

in an interrupt handler, it belongs in the main body of the code.