Tiny problem in LPC11C24 and SSP port

I know, this is not Keil related (well sort of, I use the tools :) but I know there are a lot of people here with a lot of knowledge!

Device is a LPC11C24 which is connected to a SD card using SSP1 (CS is done "manually", not using SSEL functionality).

I have used some of the example code for the TX and RX routines (non interrupt driven), and for some odd reason I can get both functions to lock up!

The transmit and receive routines:

void sspSend (uint8_t *buf, uint32_t length)
{
  uint32_t i;
  uint8_t Dummy = Dummy;

  for (i = 0; i < length; i++)
  {
    /* Move on only if NOT busy and TX FIFO not full. */
    while ((LPC_SSP1->SR & (SSP_SR_TNF_NOTFULL | SSP_SR_BSY_BUSY)) != SSP_SR_TNF_NOTFULL);
    LPC_SSP1->DR = *buf;
    buf++;

// !!!!   while ( (LPC_SSP1->SR & (SSP_SR_BSY_BUSY|SSP_SR_RNE_NOTEMPTY)) != SSP_SR_RNE_NOTEMPTY );
    while ((LPC_SSP1->SR & SSP_SR_BSY_BUSY));
    /* Whenever a byte is written, MISO FIFO counter increments, Clear FIFO
    on MISO. Otherwise, when sspReceive is called, previous data byte
    is left in the FIFO. */
    Dummy = LPC_SSP1->DR;
  }

  return;
}

void sspReceive(uint8_t *buf, uint32_t length)
{
  uint32_t i;

  for ( i = 0; i < length; i++ )
  {
    /* As long as the receive FIFO is not empty, data can be received. */
          LPC_SSP1->DR = 0xFF;

    /* Wait until the Busy bit is cleared */
// !!!!    while ( (LPC_SSP1->SR & (SSP_SR_BSY_BUSY|SSP_SR_RNE_NOTEMPTY)) != SSP_SR_RNE_NOTEMPTY );
    while ((LPC_SSP1->SR & SSP_SR_BSY_BUSY));

    *buf = LPC_SSP1->DR;
    buf++;
  }

  return;
}

If the original example code is used (the code after // !!!!) they will once in a while, lock up. However, if I only use the SSP_SR_BSY_BUSY flag they both work perfectly (AFAIK)
I have had a counter increment in the while loop, and I can see that some time elapses (as it should) waiting for the BSY bit to become 0.

So, basically what I'm saying is the code is working (now) with the modified while loop, but I don't feel too comfortable as all the examples I have found uses the original while loop (looking at the TNF/RNE bit together with the BSY bit).