One common cause of corrupt files is closing an application unexpectedly - like when the power goes down or the computer cord is pulled out of the wall - or even if the computer freezes and you have to shut it off without closing the applicaiton. If an application doesn't shutdown in an organized fashion, the file(s) that are open at the time of the unexpected shutdown may become lost or corrupt. Depending how bad the corruption is, sometimes you can recover by copying the good parts of the text into a new file. Hope this helps.