A quick observation on your code. Why compare $fileage against $modtime twice? The use of the two different file tests is confusing me as well.

If (($fileage <= $modtime) && (-d $_)) {
   # at this point we know $_ *must* be a directory
   if ($fileage <= $modtime) && (-f $_)) {
      # this -f test won't work because you are
      # testing $_ again and you've just 
      # established that $_ is a directory
[download]