read this pdf for some fun examples of the problems they have had to deal with, here's one of my favorites:

"One card game tried to make changes to the system.ini file but ended up destroying it. The game read the system.ini file a line at a time into an 80-character buffer, made any necessary changes, and wrote the result to a temporary file. If any line contained more than 80 characters, the buffer overflowed and corrupted the next variable on the stack, which happened to be the name of the temporary file! Once the changes were made, the program deleted the system.ini file and renamed the temporary file to system.ini. But the rename operation failed because the name of the temporary file was corrupted by the extra-long line.The result: a system with no system configuration file.In other words, installing this program rendered your system unbootable.The fix from the operating system side was to go through all the components of the system that used the system.ini file and make sure none of them ever wrote lines longer than 80 characters."