log files deleted

Somehow my rails log files get deleted after some time.

The log files do get created properly when I restart my mongrel
server. I usually have tail -f on the log files and they function
well even after the files don't exist anymore according to the file
system.

I use the standard development.log and another other log file that I
create as follows:

logfile_query = File.open ( "#{RAILS_ROOT}/log/query.log", 'a' )
logfile_query.sync = true
logger_query = StatsLogger.new ( logfile_query )
silence_warnings { Object.const_set "LOGGER_QUERY", logger_query }