LoopBack fails for the second time

Hi,
I am new to this group. I am using cypress fx2lp usb controller. 

I have written a loopback firmware for it and successfully downloaded on
its ram.

On the host side I have written an application which opens the usb device,
send some data, read it back, verify and close the device.

When I send 512B for the first time loopback works but when I send
anything after that loopback fails. Following is code for TD_Init() and
TD_Poll().

void TD_Init()
{
	
	CPUCS 			= 0x12;  // 48 mhz and CLKOUT enabled
	SYNCDELAY;
	IFCONFIG        = 0xE3;

	// EP 2 4 6 8 Configuration
	SYNCDELAY;
	EP2CFG          = 0xE2;   // IN   BULK  512  Double-Buffered  
	SYNCDELAY;
	EP4CFG          = 0xA0;   // OUT  BULK  512  Double-Buffered
	SYNCDELAY;
	EP6CFG          = 0xE2;   // IN   BULK  512  Double-Buffered
	SYNCDELAY;
	EP8CFG          = 0xA0;   // OUT  BULK  512  Double-Buffered

	// FIFO Reset
	SYNCDELAY;
	FIFORESET = 0x80;
	SYNCDELAY;
	FIFORESET = 0x02;
	SYNCDELAY;
	FIFORESET = 0x04;
	SYNCDELAY;
	FIFORESET = 0x06;
	SYNCDELAY;
	FIFORESET = 0x08;
	SYNCDELAY;
	FIFORESET = 0x00;
	
	// Out EP 4 8 Byte Count
	// Out EP's do not come up armed
	SYNCDELAY;
	EP4BCH = 0x00;                     // Arm EP4OUT by writing to low byte
count twice (double buffered)      
	SYNCDELAY;
	EP4BCL = 0x80;                     // Arm EP4OUT by writing to low byte
count twice (double buffered)      
	SYNCDELAY;
	EP4BCH = 0x00;                     // Arm EP4OUT by writing to low byte
count twice (double buffered)      
	SYNCDELAY;
	EP4BCL = 0x80;                  
	SYNCDELAY;
	EP4BCH = 0x00;                     // Arm EP4OUT by writing to low byte
count twice (double buffered)      
	SYNCDELAY;
	EP8BCL = 0x80;                     // Arm EP8OUT by writing to low byte
count twice (double buffered)           
	SYNCDELAY;
	EP4BCH = 0x00;                     // Arm EP4OUT by writing to low byte
count twice (double buffered)      
	SYNCDELAY;
	EP8BCL = 0x80;
	
	AUTOPTRSETUP |= 0x01;
}

void TD_Poll(void)             
{
	
	WORD i;
	WORD count;

	if( !(EP2468STAT & bmEP4EMPTY) )
	{ 	// check EP4 EMPTY(busy) bit in EP2468STAT (SFR), core set's this bit
when FIFO is empty

		if( !(EP2468STAT & bmEP2FULL) )
		{  	// check EP2 FULL(busy) bit in EP2468STAT (SFR), core set's this bit
when FIFO is full

			APTR1H = MSB( &EP4FIFOBUF );
			APTR1L = LSB( &EP4FIFOBUF );

			AUTOPTRH2 = MSB( &EP2FIFOBUF );
			AUTOPTRL2 = LSB( &EP2FIFOBUF );

			count = (EP4BCH << 8) + EP4BCL;

			// loop EP4OUT buffer data to EP2IN
			for( i = 0x0000; i < count; i++ )
			{
				// setup to transfer EP4OUT buffer to EP2IN buffer using
AUTOPOINTER(s)
				EXTAUTODAT2 = EXTAUTODAT1;
			}
			
			EP2BCH = EP4BCH;  
        	SYNCDELAY;  
       	 	EP2BCL = EP4BCL;        // arm EP2IN
        	SYNCDELAY;                    
        	EP4BCL = 0x80;          // re(arm) EP4OUT
        	SYNCDELAY;                    
     	}
  	}

  	if( !(EP2468STAT & bmEP8EMPTY) )
  	{ // check EP8 EMPTY(busy) bit in EP2468STAT (SFR), core set's this bit
when FIFO is empty
    
		if( !(EP2468STAT & bmEP6FULL) )
     	{  // check EP6 FULL(busy) bit in EP2468STAT (SFR), core set's this
bit when FIFO is full
        
			APTR1H = MSB( &EP8FIFOBUF );
        	APTR1L = LSB( &EP8FIFOBUF );

        	AUTOPTRH2 = MSB( &EP6FIFOBUF );
        	AUTOPTRL2 = LSB( &EP6FIFOBUF );

        	count = (EP8BCH << 8) + EP8BCL;

        	// loop EP8OUT buffer data to EP6IN
        	for( i = 0x0000; i < count; i++ )
        	{
           		// setup to transfer EP8OUT buffer to EP6IN buffer using
AUTOPOINTER(s)
           		EXTAUTODAT2 = EXTAUTODAT1;
        	}
        	
			EP6BCH = EP8BCH;  
        	SYNCDELAY;  
        	EP6BCL = EP8BCL;        // arm EP6IN
        	SYNCDELAY;                    
        	EP8BCL = 0x80;          // re(arm) EP8OUT
        	SYNCDELAY;                    
     	}
  	}

}

I get the following error on second time..
------------------------------------------
usb 1-2: bulk timeout on ep2in
usb 1-2: usbfs: USBDEVFS_BULK failed ep 0x82 len 512 ret -110
usb 1-2: bulk timeout on ep6in
usb 1-2: usbfs: USBDEVFS_BULK failed ep 0x86 len 512 ret -110
--------------------------------------------------------------

If anyone know about this problem kindly reply.