Lpc2000

Update to "LPC214x: USB hangs after some hours":

I went back to the original KEIL USBMEM example 
(http://www.keil.com/download/files/lpc2148_usbmem.zip) and stressed 
it with some simple stream-io code to exclude my driver/application 
(not very nice, but does the job, call this code with the USBMEM 
device letter as parameter):

int main(int argc, char* argv[])
{
  int           iResult = 0;
  char          cFile[] = "C:\\Testfile.txt";
  unsigned char data[1024];

  if (1 == argc)
  {
    char dev;

    printf("Device-Letter: ");
    scanf("%c", &dev);

    // patch device letter
    cFile[0] = dev;
  }
  else if (2 == argc)
  {
    // patch device letter
    cFile[0] = argv[1][0];
  }
  else
  {
    printf("USAGE: TestUSBMasStorage [C|D|E|...]\n");
    iResult = 1;
  }

  if (0 == iResult)
  {
    FILE* f;
    int i;

    // fill buffer
    for (i = 0 ; i < sizeof(data) ; i++)
    data[i] = (unsigned char)(i & 0xFF);

    for (i = 0 ; 0 == iResult ; i++)
    {
      printf("%d\r", i);

      if (NULL != (f = fopen(cFile, "wb")))
      {
        fwrite(data, sizeof(data), 1, f);
        fflush(f);
        fclose(f);

        _flushall();

        // read/compare data
        if (NULL != (f = fopen(cFile, "rb")))
        {
          unsigned char cmp[sizeof(data)];

          if (1 != fread(cmp, sizeof(cmp), 1, f))
            iResult = 2;
          else if (0 != memcmp(data, cmp, sizeof(data)))
          {
            iResult = 6;
          }
          fclose(f);
          _flushall();
        }
        else
          iResult = 4;
      }
      else
        iResult = 3;
    }
  }

  if (0 == iResult)
    printf("\nSuccess!");
  else
    printf("\nError: %d\n", iResult);

  return iResult;
}


With this stress the USBMEM device will hang within seconds.
The error looks the same I have in my own firmware, I reported the 
problem (http://groups.yahoo.com/group/lpc2000/message/12316).

Has anybody solved this problem ?

Gregor