SdFat library with I2C and SoftwareSerial

Thanks for the info, i will attemept to build one of these. I did resolve the problem with the sketch by changing over to hardware serial, i replaced

  unsigned long start = millis();
  do 
  {
    while (ss.available())
      gps.encode(ss.read());

with

  unsigned long start = millis();
  do 
  {
    while (Serial.available())
      gps.encode(Serial.read());

and everything is working.

Thanks again for your help and info.