I wrote a logging application for my Tungsten T
that logs about 300 bytes every 1/4 second to
an SD card file via VFSFileWrite.  Doing the math,
the file grows about 4mb per hour.  

   My process was to generate log files until the card
was nearly full, then delete them all and start over.
After 2 weeks of perfect operation, I got a 
CardBadSector error from my App and could not even
format it in a Windows card reader-"Invalid Track 0".
This represents about 5 complete fill-the-card,
erase-the-card cycles with my Lexar 256mb sd card
before failure (using 168 hours per week).  Spec
is > 100,000 write cycles.

   My question is, what am I missing?  I don't open
and close the file except when I complete a logging
session, so I am only doing 1 write during each
pass through the card, right?  Or is the FAT updated
each time the file grows by 300 bytes, even though
I don't close or flush it?  I really can't afford to
buy a new 256mb card every two weeks.  Any help
would be appreciated.

Notes:
* Sensor is an accelerometer; hence the sample rate
* Have tried PalmRamDisk, but I require space for
  24 hours of unattended logging, so it's not suitable
* have though about microdrive, but it's not available
  in the "sd slot" form factor


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