Loss of file data

I have some software which can be memory intensive. The software deals with files in text format. Every once in a while a user will complain about a file missing its contents. I'm using the FileWriter class to write out data and the FileReader class to read in data. Would anyone have any suggestions on what can cause data from a file to be eliminated? Thanks.

[376 byte] By [ysh@eden] at [2007-9-30 4:08:55]