I executed 20 or 25 iterations of formating with Windows XP Pro SP2 using Fat. (Not quick format) I also used the Panasonic SD Formatter 2.0 (2.0.0.2) to format using specific SD Protocol. (Just in case) The device I used is the built - in SD Card reader with the Panasonic Toughbook. The Panasonic utility is the only formatter recommended by the SD Card Association.
http://www.sdcard.org/about/
"In January 2000, Matsushita Electric Industrial Co., Ltd. (Panasonic), SanDisk Corporation and Toshiba Corporation established the SD Card Association as a new industry-wide organization charged with setting industry standards and promoting wide acceptance for the SD Memory Card in digital applications. "
So I feel good about using both the OEM reader and the OEM software on a Panasonic OEM device. One of three organizations that established the technical and specification standards for the SD Memory Card.
I used the SD card (512mg )purchased from SparkFun (Didn’t work at all - ever - PC or SF Device) SanDisk (64mg and 2gb) which worked about 80% of the time and Kingston (2gb) which worked about 5% of the time. The size of the card didn’t seem to have an affect but I think this is because of my testing procedure.
Each time I went through the testing I formatted the SD Card, pulled the card out of the PC, inserted into Sparkfun device, powered up, ran for a few minutes, selected the stop button, pulled the SD Card and read with the PC.
After a few iterations I concentrated on the SanDisk Cards as they had the most success.
Almost all the time, I could read with the PC. The Sparkfun device never crashed the SD Card as long as I selected the stop button first before removing it.
If I attempted to power up the device without removing the SD Card after the first iteration (the creation of the GPSCONFIG.TXT file), I would get a -6 Error about 10 - 20 % of the time. Sometimes a -2 error. If I removed the SD Card and edited the GPSCONFIG.TXT file with a programmers editor, it would always fail with a -6. If I edited with EDIT.EXE in XP Pro SP2 It would almost always work.
My guess is that the type of editor used changes the file in some significant way either by writing to the FAT a strange way or changing the file in some significant way. I did notice that the initial edit using the programmers editor showed that the initial GPSCONFIG.TXT contained extra 0x0A s where there should have been 0x0D 0x0A.
If you like I can provide a spreadsheet detailing the exact proceedures I took with the results. (I would rerun them)